Electrolysis device, method for measuring the concentration of a gas component in an electrolysis device, computer program product, use of a measurer and simulation program product

Abstract

This invention relates to an electrolysis apparatus, a method for measuring the concentration of gaseous components in the electrolysis apparatus, a computer program product, an application of the measuring instrument, and a simulation program product. The electrolysis apparatus (10) includes a separation membrane (16) for generating hydrogen (13) and oxygen (15) from water. The electrolysis apparatus (10) has a first conduit (12) for extracting hydrogen (15) from a hydrogen fluid (17), and a measuring instrument (20) for detecting impurities (18), such as oxygen impurities, in the hydrogen fluid (17) is arranged in a region of the first conduit (12). According to the invention, the measuring instrument (20) is designed to detect acoustic characteristic parameters in the hydrogen fluid (17). The invention also relates to a method (100) for determining the concentration (32) of impurities (18) in the electrolysis apparatus (10). The invention further relates to a computer program product (45) for performing this method (100) and a simulation program product (60) for simulating the operating behavior of such an electrolysis apparatus (10). The present invention also relates to the application of a measuring device (20) in an electrolysis apparatus (10) designed to measure the velocity of sound (42) in a mixed gas (11).

Description

Technical Field

[0001] This invention relates to an electrolysis apparatus and a method for measuring the concentration of gaseous components in such an apparatus. The invention also relates to a computer program product for performing this method and the corresponding application of the measuring instrument. Furthermore, the invention relates to a simulation program product for simulating the operating behavior of a corresponding electrolysis apparatus. Background Technology

[0002] A MEMS (microelectromechanical system) based microphone is known from international application WO 2022 / 039596 A1, which has a body with a recess, a resonator, and a ventilation system. The resonator is designed to vibrate at a mechanical resonant frequency higher than the characteristic equilibrium frequency.

[0003] The paper "Speed ​​of sound measurements in gas-mixtures at varying compositions using an ultrasonic gas flow meter with silicon based transducers" (authors Torbjoern Loefqvist, Kestutis Sokas, and Jerker Delsing) describes the measurement of sound velocity in monoatomic, diatomic, and triatomic gases. Argon, oxygen, or carbon dioxide is added as additives to air or nitrogen. The paper discloses that the concentration and molar composition of the corresponding gas mixtures can be determined by measuring temperature and sound velocity.

[0004] Patent application IN 201941019317 A discloses a method for determining the concentration of a gas in a gas mixture. This method is based on photoacoustic spectroscopy and is used to influence the velocity of sound within the gas mixture by the concentration of its components.

[0005] Document DE 10 2019 129 430 B4 discloses a method for continuously determining the mixing ratio of combustible gas and oxidizing gas in an explosive high-pressure environment. A sub-stream is provided in a measuring chamber, where the components are determined by gas measurement. Oxygen impurities are identified, particularly in a hydrogen fluid. Summary of the Invention

[0006] Electrolysis equipment produces hydrogen and oxygen in molecular form during operation. The formation of flammable, detonating gas mixtures must be avoided. Wear and tear on the separation membrane in the electrolysis unit can lead to oxygen impurities on the hydrogen side of the membrane. A method for safely, quickly, and reliably detecting these oxygen impurities is needed. The fundamental objective of this invention is to provide a feasible method for advantageously identifying the generation of potentially hazardous gas mixtures in electrolysis equipment.

[0007] This objective is achieved by an electrolysis apparatus according to the invention. The electrolysis apparatus includes a separation membrane designed to perform electrolytic separation of water thereon, separating water into hydrogen and oxygen, i.e., separating them into essentially molecular hydrogen and essentially molecular oxygen. The hydrogen produced here can be discharged as a hydrogen fluid. Similarly, the oxygen produced at the separation membrane can be discharged as an oxygen fluid. The electrolysis apparatus also includes a first conduit designed for discharging the hydrogen fluid, for example, into a compressor or container. A measuring device is disposed in a region of the first conduit, designed for detecting impurities in the hydrogen fluid, such as oxygen impurities and / or nitrogen impurities. The measuring device can be fluidly connected to the first conduit and can be traversed by a portion of the hydrogen fluid. The measuring device can be designed to periodically or continuously monitor impurities in the hydrogen fluid, particularly oxygen impurities and / or nitrogen impurities. According to the invention, the measuring device is designed to detect acoustic characteristic parameters in the hydrogen fluid. By detecting these acoustic characteristic parameters, the presence of oxygen impurities in the hydrogen fluid can be detected. The invention is particularly based on the understanding that oxygen impurities, even at low concentrations, can cause significant changes in the acoustic characteristic parameters of the hydrogen fluid. In particular, the changes in acoustic characteristic parameters caused by oxygen impurities in hydrogen fluid are significantly stronger than those caused by hydrogen impurities in oxygen fluid at the opposite concentration ratio. Therefore, the electrolysis apparatus according to the invention ensures early identification of oxygen impurities in the hydrogen fluid. Similarly, by identifying the presence of oxygen impurities in the hydrogen fluid, the automatic identification of damaged or worn separation membranes in the electrolysis apparatus can be accelerated. Rapid identification of damaged or worn separation membranes below the boundary value where oxygen impurities may cause an explosion hazard allows for timely replacement of the separation membrane, ensuring efficient operation of the electrolysis apparatus. Furthermore, the reduction in nitrogen impurities is detectable after rinsing the electrolyzer with nitrogen. This can be identified by precise measurement when the electrolysis apparatus can restart production and produce sufficiently pure hydrogen. The electrolysis apparatus according to the invention can therefore operate continuously, safely, reliably, and economically in a simple manner.

[0008] In the electrolysis apparatus according to the invention, the acoustic parameter used for detecting impurities is the velocity of sound in the hydrogen fluid. Specifically, the velocity of sound in the hydrogen fluid changes significantly when oxygen and / or nitrogen impurities are present. When 0.1 volume percentage of hydrogen is added to an originally pure oxygen fluid, the density of the mixed gas changes by approximately 0.001 kg / m³. 3 The change was from 1.428 kg / m 3It becomes 1.429 kg / m 3 When 0.1% by volume of oxygen is added to a previously pure hydrogen fluid, the density of the mixture also changes by approximately 0.001 kg / m³. 3 The change was from 0.085 kg / m 3 It becomes 0.084 kg / m 3 Therefore, compared to oxygen-impregnated oxygen fluids, hydrogen-impregnated fluids exhibit approximately 16 times greater relative density changes. Since oxygen and nitrogen have similar molecular weights, nitrogen impurities also produce a similar effect. The velocity of sound in the corresponding gas mixture depends on its density. Therefore, it is permissible to detect the velocity of sound in hydrogen fluids containing oxygen and / or nitrogen impurities, thereby allowing for the detection of relative density changes. Accordingly, the measuring device in the claimed electrolysis apparatus can be designed as a sound velocity measuring device. Such a sound velocity measuring device is readily available and offers higher measurement accuracy. Thus, even at low oxygen or nitrogen concentrations, impurities entering the hydrogen fluid can be reliably identified.

[0009] In the electrolysis apparatus according to the invention, the measuring device also includes a microphone disposed in the measuring chamber. The microphone is arranged in the middle section along the main axis. The microphone is particularly capable of being centrally positioned along the measuring chamber. The main axis extends substantially from one end face of the measuring chamber to the opposite end face. The longitudinal direction of the measuring chamber is substantially defined by the orientation of the main axis. The microphone is centrally positioned, where antinodes of even-order harmonic vibrations exist. Maximum amplitude, i.e., acoustic loudness, exists in the antinode region, particularly at its extreme points. In the case of even-order harmonic vibrations, a central antinode that can be detected by the microphone is always present in the measuring chamber. Therefore, the measuring chamber requires only one microphone or a microphone device centrally positioned along the main axis. Thus, the measuring device and the electrolysis apparatus requiring protection can be manufactured economically and efficiently. Furthermore, the risk of component failure is reduced by such a reduction in the number of parts. The measuring device generally provides higher measurement accuracy and enhanced robustness.

[0010] Furthermore, the measuring instrument can be designed to excite and detect acoustic resonances in a material sample derived from a hydrogen fluid. The measuring instrument may have a generally elongated, i.e., prismatic measuring chamber into which the material sample is introduced. The measuring chamber may have end faces at both ends and be designed such that the material sample introduced from the hydrogen fluid flows substantially longitudinally, i.e., from one end face to the opposite end face through the measuring chamber. To excite the acoustic resonance, at least one end face may be provided with an acoustic emitter, also called a transducer. The acoustic emitter may be specifically designed as a piezoelectric transducer. The acoustic emitter can be tuned by a frequency generator, which can be connected to a control unit. The excited acoustic resonance may be a vibration mode of the first, second, etc., harmonics. This allows for precise frequency measurement of the harmonic vibration modes in the material sample, thereby reliably determining the sound velocity present therein. In particular, the frequency generator may be designed to excite longitudinal vibrations of the third or fourth harmonic in the measuring chamber. These vibrations exhibit significant changes in resonant frequency as the oxygen concentration in the material sample increases. This ensures the simplicity and accuracy of sound velocity measurement. It further improves the reliability of impurity detection in hydrogen fluids, especially oxygen impurities.

[0011] In addition, the measuring instrument may include at least one additional microphone disposed in the measuring chamber. By using multiple microphones, an enhanced measurement signal can be generated, thereby allowing for more accurate measurements, particularly more accurate measurements of the velocity of sound in hydrogen fluids.

[0012] Furthermore, the measuring device may be equipped with an evaluation unit designed to determine the concentration of impurities in the hydrogen fluid. The evaluation unit may be specifically designed to quantitatively determine existing impurities based on measurement signals generated during the measurement process in the measuring chamber. For this purpose, changes in the velocity of sound of a sample of substance in the hydrogen fluid can be detected, and the relative density difference relative to pure hydrogen fluid can be determined based on this. Based on the relative density difference, the concentration of impurities can be quantified. The evaluation unit may be equipped with a suitably designed computer program. Additionally, the evaluation unit may be designed as a functional unit of a control unit, and the measuring device may be equipped with this control unit. The evaluation unit may also be designed to output a warning to the user and / or data interface when the detected oxygen impurity concentration numerically exceeds a preset threshold value. Correspondingly, a notification regarding the decrease in nitrogen impurity concentration may also be output when the nitrogen impurity concentration is numerically below a corresponding preset threshold value. Alternatively or supplementarily, control commands for preset operating modes of the electrolysis unit may be output. Thus, the automatic reaction behavior of the electrolysis unit can be specifically adjusted as a whole. The electrolysis unit under protection can therefore be adapted to a wide range of safety requirements and can operate economically.

[0013] Specifically, the evaluation unit may have a bandpass filter. This bandpass filter may be designed to evaluate at least the measurement signal from a microphone in the middle of the measurement chamber. The bandpass filter may also be designed to additionally evaluate measurement signals from at least one other microphone. By using a bandpass filter, noise can be reduced, for example, allowing for more accurate measurements, particularly the velocity of sound in hydrogen fluids.

[0014] Furthermore, the measuring device of the electrolysis apparatus requiring protection can be equipped with a temperature measuring device. This temperature measuring device can be designed as a temperature sensor and designed to detect the temperature of the substance sample in the measuring chamber. Similarly, the measuring device can be designed to perform temperature compensation when determining the velocity of sound in the substance sample based on the temperature detected by the temperature measuring device. This compensates for the effect of temperature on the measured velocity of sound, thereby achieving accurate concentration measurement. The measuring device operates normally over a wide temperature range of the hydrogen fluid, and therefore can be installed at any location on the first conduit carrying the hydrogen fluid. This allows for easy retrofitting of existing electrolysis apparatuses.

[0015] In another embodiment of the invention, the measuring device on the electrolysis apparatus may be equipped with a pressure sensor. The detection of the concentration of oxygen mixed with hydrogen is pressure-dependent. In particular, there is a direct proportionality between the measured gas pressure and the gas density measurement. Accordingly, the measuring device may be designed to determine the concentration of impurities through pressure compensation. Alternatively or supplementarily, the hydrogen concentration in a sample of material from a hydrogen fluid can be determined with pressure compensation. This further improves the achievable measurement accuracy.

[0016] Furthermore, the sides defining the measuring chamber essentially along the main axis, i.e., between the end faces, can be formed from a profile body, particularly an extruded profile body. This profile body can have a wall thickness that produces a substantially uniform temperature distribution along the sides. Correspondingly, the temperature distribution within the measuring chamber is also substantially uniform. The profile body can be made of a metallic material, such as an aluminum alloy or a copper alloy. Higher thermal conductivity of the profile body is preferable. A higher wall thickness results in greater thermal inertia, thereby stabilizing the uniform temperature distribution on the sleeve surface and within the measuring chamber. The profile body can be manufactured cost-effectively over a wide range of wall thicknesses. Therefore, the measuring instrument can be manufactured cost-effectively while exhibiting better repeatability in its measurements.

[0017] Furthermore, the electrolysis unit can be equipped with a database that stores historical measurement data on oxygen impurity concentrations and provides it for evaluation. This database can be designed as a component of the electrolysis unit's control unit. Historical measurement data can be collected within the electrolysis unit itself and / or on electrolysis units of the same structure. The database can be evaluated using simulation programs where the electrolysis unit is mapped, for example, as a digital twin. This allows for targeted diagnosis of the causes of increased oxygen impurity concentrations in the hydrogen fluid, which in turn allows for the safe operation of the electrolysis unit.

[0018] This objective is also achieved by the method of the present invention for detecting impurities, such as oxygen and / or nitrogen impurities, in hydrogen fluid within an electrolysis apparatus. The hydrogen fluid is introduced into a first conduit. The method includes a first step in which the electrolysis apparatus is operated. During operation of the electrolysis apparatus, molecular hydrogen is generated at a separation membrane. When the separation membrane is damaged or worn, oxygen impurities are generated, which form a mixed gas with the molecular hydrogen and are introduced into the first conduit. After rinsing with nitrogen, nitrogen impurities remain, which mix with the hydrogen. This reduces the purity, i.e., quality, of the produced hydrogen. Impurities in the hydrogen fluid need to be detected during the process according to the method of the present invention. The method includes a second step in which the velocity of sound in the mixed gas transported through the first conduit is determined. For this purpose, the electrolysis apparatus may be equipped with a corresponding measuring device in fluid communication with the first conduit. To detect the velocity of sound in the mixed gas, a sample of the substance from the hydrogen fluid in the first conduit may be introduced into the measuring chamber of the measuring device. The second step also includes comparing the detected velocity of sound with a reference velocity of sound.

[0019] The method according to the invention further includes a third step in which the concentration of impurities in the mixed gas is determined based on the comparison results in the second step. The difference between the measured sound velocity and the reference sound velocity forms a favorable measurement index of the concentration of impurities in the hydrogen fluid, i.e., a measurement index of the mixed gas. Furthermore, in the third step, a warning is issued when the measured oxygen impurity concentration numerically exceeds a preset threshold value. This warning can be output to a user and / or data interface. Additionally, control commands can also be output, through which the operating mode of the electrolysis device can be preset. For this purpose, the electrolysis device, particularly the measuring instrument, can be equipped with an evaluation unit on which a corresponding executable computer program product can be stored.

[0020] The method according to the invention advantageously enables reliable detection of low-concentration oxygen impurities, thereby allowing for early risk mitigation intervention in the operation of the electrolysis unit. In particular, it enables rapid identification of damaged or worn separation membranes in the electrolysis unit. By replacing the separation membranes early, particularly efficient operation of the electrolysis unit can be achieved. It also enables identification of whether nitrogen impurities have been adequately flushed to produce hydrogen with the desired purity. This allows for particularly economical operation of the electrolysis unit.

[0021] In the claimed method, the basic electrolysis apparatus can be designed according to one of the above embodiments. The features of the above-described electrolysis apparatus can be applied directly to the claimed method, either individually or in combination. Therefore, the claimed method is applicable to a variety of different electrolysis apparatuses.

[0022] In another embodiment of the claimed method, the temperature and / or pressure of the detected mixed gas are considered in the second step to determine the velocity of sound. Accordingly, the determination of the velocity of sound is performed under temperature and / or pressure compensation. With temperature and / or pressure compensation, adaptive adjustments to the sample to be tested, i.e., pretreatment of the sample to reference conditions, become unnecessary. The claimed method allows direct detection of the presence of oxygen impurities in a sample having a wide range of thermodynamic states (i.e., temperature and pressure). Pressure and temperature compensation can be achieved through pure algebraic operations or characteristic graphs, thus enabling a computationally efficient solution. Therefore, the claimed method is fast, robust, and accurate. For this purpose, the electrolysis apparatus can be equipped with a corresponding temperature measuring device designed to detect the temperature of the sample in the measuring device. Furthermore, the measuring device can be equipped with a corresponding pressure sensor set to detect the pressure of the sample in the measuring device. The pressure and temperature of the sample from the hydrogen fluid can be detected accurately and intrinsically safely. The execution of temperature and / or pressure compensation can be achieved through an evaluation unit that can be coupled to the measuring device. This improves the achievable measurement accuracy while simultaneously achieving explosion-proof protection.

[0023] The aforementioned basic objectives are also achieved by a computer program product according to the invention. This computer program product is designed to receive and process measurement signals from a microphone. It is also designed to determine the concentration of oxygen impurities in a hydrogen-containing gas mixture. The determination of the oxygen impurity concentration is based on various factors, including the measurement signals transmitted from the microphone to the computer program product. According to the invention, the computer program product is configured to perform at least one embodiment of the above-described method. The corresponding methods and features of the associated electrolysis apparatus can therefore be applied individually or in combination to the computer program product according to the invention. The computer program product can be configured to be executable in an evaluation unit of the electrolysis apparatus, wherein the evaluation unit may belong to the control unit of the electrolysis apparatus. Furthermore, the computer program product can be of a monolithic design, i.e., designed to execute on a single hardware platform. Alternatively, the computer program product can be of a modular design, i.e., comprising multiple subroutines that can execute on separate hardware platforms and are interconnected via communication data links. Thus, the subroutines work together to achieve the functionality of the computer program product. The computer program product can, for example, be designed to execute on a memory programmable controller (SPS), a host computer, or a computer cloud. The claimed computer program product is capable of quickly and reliably identifying the presence of impurities with reduced computational power requirements. The computer program product may also have a data interface through which warnings can be output to the user and / or the control program of the electrolysis device.

[0024] The aforementioned objective is also achieved through the application of the measuring device according to the invention. The measuring device is configured to determine the velocity of sound in a mixture of gases containing hydrogen, particularly molecular hydrogen, and impurities, particularly oxygen and / or nitrogen impurities. According to the invention, the measuring device is used in an electrolysis apparatus. Specifically, the measuring device is used to determine the concentration of oxygen impurities in a hydrogen fluid during operation of the electrolysis apparatus, in which the products of the electrolytic reaction are discharged. The features of the measuring device and electrolysis apparatus described above can therefore be adapted individually or in combination to the application according to the invention. Measuring devices suitable for measuring the velocity of sound in mixed gases are readily available and applicable to a variety of mixed gases. The claimed application advantageously allows, for example, the use of existing measuring devices, which are set up as laboratory equipment for use in industrial electrolysis apparatuses. The electrolysis apparatus, for example, may have a velocity of sound of at least 0.25 Nm. 3 / h, especially at least 10 Nm 3 / h, preferably at least 100 Nm 3 / h, preferably at least 1000 Nm 3 Hydrogen yield per hour. Unit: Nm³ 3 / h here represents standard cubic meters per hour.

[0025] Furthermore, the objective stated at the outset is achieved through a simulation program product according to the present invention. This simulation program product contains instructions that enable a computer to simulate the operational behavior of an electrolysis apparatus upon execution. Accordingly, the simulation program product is designed to reproduce the operational behavior of the electrolysis apparatus. According to the present invention, the electrolysis apparatus is designed according to one of the embodiments described above. The simulation program product is suitable for performing operational-concurrent and / or pre-concurrent simulations of the operational behavior of a corresponding electrolysis apparatus. Similarly, the simulation program product is suitable for reproducing the previous operational state of the electrolysis apparatus based on historical operational data.

[0026] The simulation program product may have a data interface through which predetermined operating conditions for performing the simulation can be set. These predetermined operating conditions can be set by the user, another simulation-guided computer program, and / or suitable sensing technology. Predetermined operating conditions may include existing molecular hydrogen and molecular oxygen yields, the hydrogen fluid, i.e., the flow behavior of the gas mixture containing the produced molecular hydrogen, and / or the existing concentration of oxygen impurities in the hydrogen fluid. Furthermore, the temperature, pressure, density of the gas mixture, the velocity of sound present therein, control commands issued to the acoustic emitter, and / or damage indications of the electrolysis unit's separation membrane may be considered preset operating conditions.

[0027] The simulation program product may include a physics module, which may have a digital image of the electrolysis apparatus and / or a corresponding computational model. This physics module is suitable for determining at least one pre-settable parameter in the electrolysis apparatus, dependent on pre-settable operating conditions. Among the pre-settable parameters to be determined may, for example, include a measurement signal generated by resonance in the simulated measurement chamber due to simulated excitation. The physical effects upon which the corresponding action chains are based can be substantially algebraically calculated within the electrolysis apparatus. In particular, the effect of impurities on the velocity of sound in the mixed gas can be substantially idealized because the wall thickness of the measurement chamber profile ensures the homogeneity of the temperature distribution within the measurement chamber. During simulated operating behavior, interference effects and / or transient effects are negligible without limiting realism. This invention is based on a surprising discovery that the employed measuring instrument and the thermodynamic effects occurring within it are particularly well-suited for simulation.

[0028] The analog measurement signal can be, for example, a measurement signal from an analog microphone. Alternatively or supplementarily, the velocity of sound in the gas mixture of the material sample located in the analog measurement chamber, as determined thereby, can also be used as a measurement signal. This can, for example, verify whether the determined impurity concentration, i.e., the concentration of oxygen impurities and / or nitrogen impurities, is likely to actually exist, or whether at least one component of the electrolysis apparatus, particularly the microphone, temperature sensor, and / or pressure sensor in the measurement chamber, may be damaged. For this purpose, the simulation program product can, for example, be connected to a database containing historical measurement data. A sudden increase in impurity concentration may usually be caused by sensor malfunction, while a sustained increase may be caused by degradation of the separation membrane. The simulation program product may incorporate artificial intelligence or be coupled with artificial intelligence to perform such plausible verification.

[0029] Furthermore, the simulation program product may include a data interface through which preset parameters can be output as simulation results. The simulation results can be output to a user and / or other simulation-oriented computer programs via this data interface. Alternatively or additionally, the simulation results can be output to the control program of the electrolysis device to issue control commands that switch the electrolysis device, which has identified an abnormal operating state, to a safe operating state. The simulation program product according to the invention can constitute a so-called digital twin, as described, for example, in document US 2017 / 286572 A1. The disclosure of US 2017 / 286572 A1 is incorporated herein by reference. The electrolysis device, particularly its measuring instruments, on which the simulation program product according to the invention is based can be simulated in a surprisingly simple manner. At the same time, the simulation program product provides a higher degree of realism. Overall, the simulation program product of the invention is suitable for monitoring the operation of a corresponding electrolysis device. This monitoring can be performed substantially in real time, which allows the electrolysis device to respond particularly quickly and therefore operate safely. Therefore, the technically available lifespan of easily worn components in the simulated electrolysis unit can be more fully utilized, allowing for less interrupted and more economical operation. This simulation program product can be used to determine when oxygen impurities in the hydrogen fluid are expected to reach a critical concentration by pre-simulating the operation of the electrolysis unit. Maintenance and operation of the electrolysis unit can thus be planned before approaching the critical concentration. Overall, the simulation program product of this invention enables particularly advantageous operation of the corresponding electrolysis unit. Attached Figure Description

[0030] The present invention will now be described in detail with reference to the accompanying drawings and various embodiments. The drawings should be understood in a complementary manner, meaning that the same reference numerals in different drawings have the same technical meaning. Features of the various embodiments can also be combined with each other. Furthermore, the features of the embodiments shown in the drawings can be combined with the features summarized above. Specifically, the following is shown:

[0031] Figure 1A schematic diagram showing one embodiment of the claimed electrolysis apparatus is illustrated;

[0032] Figure 2 A longitudinal cross-sectional view of the measuring device of an embodiment of the claimed electrolysis apparatus is shown. Detailed Implementation

[0033] exist Figure 1 The diagram illustrates the construction of one embodiment of the claimed electrolysis apparatus 10. The electrolysis apparatus 10 includes an electrolytic cell 39, through which an electrolytic reaction occurs during operation of the apparatus 10, yielding molecular hydrogen 13 and molecular oxygen 15 from water. The apparatus 10 also includes a separation membrane 16 disposed within the electrolytic cell 39. The obtained molecular hydrogen 13 is discharged from the electrolytic cell 39 through a first conduit 12, and molecular oxygen 15 is discharged through a second conduit 14. Therefore, hydrogen fluid 17 is present in the first conduit 12, and oxygen fluid 19 is present in the second conduit 14. When the separation membrane 16 is damaged and / or worn, oxygen enters the first conduit 12, causing the hydrogen fluid 17 to form a mixed gas 11 consisting of molecular hydrogen 13 and oxygen impurities 18. When the oxygen impurities 18 in the mixed gas 11 reach a sufficient concentration, the mixed gas becomes a flammable gas. In addition to oxygen impurities 18, nitrogen impurities (not shown in detail in the diagram) may also be present in the hydrogen fluid 17.

[0034] Measuring device 20 is hydraulically connected to first conduit 12, thereby allowing material sample 22 to be continuously, i.e., introduced into measuring device 20 from mixed gas 11 during operation. Material sample 22 represents the hydrogen fluid 17 containing oxygen impurity 18 in first conduit 12, i.e., the same mixed gas 11, in terms of its composition of molecular hydrogen 13 and oxygen impurity 18. Measuring device 20 is connected to first conduit 12 via supply conduit 21 and outlet conduit 23 through which material sample 22 flows. Measuring device 20 is connected to evaluation unit 40, which in turn belongs to control unit 50 of electrolysis device 10. Computer program product 45 is executablely stored on evaluation unit 40, which is designed to detect the concentration 32 of oxygen impurity 18 in material sample 22, thereby also detecting the concentration of oxygen impurity in hydrogen fluid 17. Computer program product 45 is adapted to receive and evaluate measurement signals 27 from measuring device 20. The evaluation unit 40 is connected to the control unit 50 via a data interface 44, enabling the electrolysis unit 10 to be controlled in response to the detected concentration 32 of oxygen impurities 18. For this purpose, the control unit 50 is equipped with a frequency generator and an executable control program 55 stored thereon, which is designed to generate and output control commands 29. Furthermore, a simulation program product 60, designed as a digital twin of the electrolysis unit 10, is executablely stored on the evaluation unit 40.

[0035] A method 100 for detecting the concentration 32 of oxygen impurities 18 in hydrogen fluid 17 can be implemented on the electrolysis apparatus 10. Method 100 begins with a first step 110, in which the electrolysis apparatus 10 is operated, such as... Figure 1 As shown, at least hydrogen fluid 17 from electrolyzer 39 is present. Method 100 also includes a second step 120, in which the velocity of sound 42 in the mixed gas 11 supplied to the measuring device 20 as a material sample 22 is detected by the measuring device 20. The detected velocity of sound 42 is compared with a reference velocity of sound 41 by a computer program product 40 in the second step 120. Furthermore, method 100 includes a third step 130, which is also performed in the computer program product 45. In the third step 130, the concentration 32 of oxygen impurities 18 in the mixed gas 11 is determined. This is based on the comparison performed in the second step 120. Also in the third step 130, a warning 48 is output when the determined concentration 32 of oxygen impurities 18 numerically exceeds a preset threshold value 34.

[0036] according to Figure 1 The measuring device 20 of the illustrated embodiment is in Figure 2 The image is schematically shown in longitudinal section. For example... Figure 1 As shown, the measuring device 20 can be used in the electrolysis apparatus 10. The measuring device 20 is designed, especially in applications such as... Figure 1 In the method 100 shown for detecting the concentration 32 of oxygen impurities 18 in hydrogen fluid 17, a second step 120 is performed. The measuring device 20 includes a measuring chamber 30 through which a material sample 22 flows during operation. The material sample 22 is input through a supply pipe 21 and output through an outlet pipe 23. The measuring chamber 30 is permeated by the material sample 22 along the flow direction 31. Furthermore, the measuring chamber 30 has a profile body 37 that extends substantially along a main axis 25. The profile body 37 has a wall thickness 35 on its outer surface, such that the profile body 37 acts as a heat conductor and thermal buffer. The profile body 37 is made of a metallic material, such as an aluminum alloy, thereby presenting a substantially uniform temperature distribution in the material sample 22 within the measuring chamber 30. The profile body 37 and the measuring chamber 30 are closedly formed at their end faces 28.

[0037] An acoustic emitter 24 is disposed on one of the end faces 28, which is controlled by the evaluation unit 40 via control command 29. The acoustic emitter 24 is designed to be tunable, so that sound waves with a preset frequency or wavelength can be generated in the measurement chamber 30 and thus in the material sample 22. In particular, harmonic vibrations 49 can be generated, wherein... Figure 2 The first harmonic vibration is illustrated exemplarily in the diagram. Figure 2The sound pressure of harmonic vibration 49 is shown. A microphone 26 is positioned along the main axis at the midpoint 33 of the wall of the measuring chamber 30. This microphone 26 is suitable for detecting harmonic vibration 49. By positioning the microphone 26 at the midpoint 33, it is suitable for detecting the maximum amplitude of even-order harmonic vibration 49. For this purpose, the microphone 26 is connected to the evaluation unit 40, allowing the measurement signal 27 to be transmitted to the evaluation unit 40. By performing a corresponding frequency scan on the acoustic emitter 24, the excitation frequency at which the acoustic emitter 24 generates even-order harmonic vibration 49 in the measuring chamber 30 can be identified. The existing resonant frequency of the harmonic vibration 49 can also be determined by the microphone 26. There is a physical correlation between the existing resonant frequency in the material sample 22 and the velocity of sound 42 therein. In the second step 120, the existing velocity of sound 42 is compared with a reference velocity of sound 43, and the velocity difference is determined. The reference velocity of sound 41 corresponds to the velocity of sound in the hydrogen fluid 17 free of oxygen impurities 18. The velocity difference represents a measure of the concentration of oxygen impurities 18. The concentration 32 of oxygen impurity 18 is determined in a third step 130, which is not shown in detail.

[0038] Measuring device 20 has a temperature measuring device 36 and a pressure sensor 38 mounted on the wall of measuring chamber 30, designed to detect the current temperature and pressure within measuring chamber 30. The temperature measuring device 36 and pressure sensor 38 are coupled to evaluation unit 40 and adapted to transmit the corresponding measured values ​​as measurement signals 27 to evaluation unit 40. Based on the measurement signals 27 from the temperature measuring device 36 and / or pressure sensor 38, temperature and / or pressure compensation is performed to determine the velocity of sound 42 in the material sample 22. The corresponding pressure and / or temperature compensation is provided by a computer program product 45 on evaluation unit 40.

[0039] When, for example, in Figure 1As shown in the third step 130, when the concentration 32 of oxygen impurity 18 is determined and exceeds a preset threshold value 34, a warning 48 is also output to the user and / or data interface 44. The evaluation unit 40 is part of the control unit 50 of the electrolysis device 10 and is connected to the control unit via the data interface 44. A control program 55 is executablely stored on the control unit 50, through which control commands 29 (not shown in detail) for preset operating modes of the electrolysis device 10 can be output. A database 52 is also provided in the control unit 50, which analytically provides the concentration 32 of oxygen impurity 18 obtained from historical measurement data. Historical measurement data can be collected in the electrolysis device 10 itself and / or on similar electrolysis devices. The database 52 can be analyzed and evaluated via a digital twin 60 of the electrolysis device 10. Thus, when the concentration 32 of oxygen impurity 18 increases, its cause can be determined. Furthermore, the electrolysis device 10 is mapped in the digital twin 60, which is executed in real time on the evaluation unit 40. The digital twin 60 is designed to identify defective components of the electrolysis unit 10, particularly such as Figure 1 The damaged or worn separation membrane 16 is shown.

Claims

1. An electrolysis apparatus (10) comprising a separation membrane (16) for generating hydrogen (13) and oxygen (15) from water and a first conduit (12) for extracting hydrogen (13) in a hydrogen fluid (17), wherein, A measuring device (20) for detecting impurities (18) in the hydrogen fluid (17) is arranged in the region of the first pipe (12), wherein the impurities (18) are oxygen impurities. The measuring device (20) is characterized in that it is designed to detect acoustic characteristic parameters in the hydrogen fluid (17) to detect the presence of the oxygen impurities in the hydrogen fluid (17), wherein the acoustic characteristic parameter is the speed of sound (42) in the hydrogen fluid (17) and the measuring device (20) is designed as a sound speed measuring device, wherein the measuring device (20) has a microphone (26) arranged in the middle section (33) along the main axis (25) of the measuring chamber (30).

2. The electrolysis apparatus (10) according to claim 1, characterized in that, An acoustic emitter (24) is arranged at the end face (28) of the measuring chamber (30) of the measuring instrument (20). The acoustic emitter is designed to be tunable and is designed to generate even-order harmonic vibrations (49) in the measuring chamber (30).

3. The electrolysis apparatus (10) according to claim 1 or 2, characterized in that, The measuring instrument (20) is designed to excite and detect acoustic resonances in a material sample (22) taken from the hydrogen fluid (17).

4. The electrolysis apparatus (10) according to claim 3, characterized in that, The measuring instrument (20) has at least one additional microphone (26) arranged in the measuring chamber (30).

5. The electrolysis apparatus (10) according to any one of claims 1 to 4, characterized in that, The measuring device (20) is equipped with an evaluation unit (40) designed to determine the concentration (32) of the impurity (18) in the hydrogen fluid (17).

6. The electrolysis apparatus (10) according to claim 5, characterized in that, The evaluation unit (40) has a bandpass filter for evaluating the measurement signal (27) from the microphone (26).

7. The electrolysis apparatus (10) according to any one of claims 1 to 6, characterized in that, The measuring device (20) is equipped with a temperature measuring device (36).

8. The electrolysis apparatus (10) according to any one of claims 1 to 7, characterized in that, The measuring device (20) is equipped with a pressure sensor (38).

9. A method (100) for detecting the concentration (32) of impurities (18) in hydrogen (13) in hydrogen fluid (17) in an electrolysis apparatus (10), comprising the following steps: a) Operate the electrolysis unit (10) and introduce a mixed gas (11) containing hydrogen (13) and impurities (18) into the first pipe (12); b) Detect the speed of sound (42) in the gas mixture (11) and compare it with a reference speed of sound (43); c) Determine the concentration of impurity (18) in the mixed gas (11) according to the comparison in step b), and output a warning (48) when the determined concentration (32) of the impurity (18) exceeds a preset boundary value (34), wherein the impurity (18) is an oxygen impurity, characterized in that the method (100) is performed on an electrolysis apparatus (10) according to any one of claims 1 to 8.

10. The method (100) according to claim 9, characterized in that, In step b), the velocity of the sound (42) is determined taking into account the detected temperature and / or detected pressure of the mixed gas (11).

11. A computer program product (45) for receiving and evaluating measurement signals (27) from a microphone (26) designed to determine the concentration (32) of impurities (18) in a gas mixture (11) containing hydrogen (13), characterized in that, The computer program product (45) includes instructions that cause the electrolysis apparatus (10) according to any one of claims 1 to 8 to perform the method (100) according to claim 9 or 10.

12. A simulation program product (60) comprising instructions that, when executed by a computer, cause the computer to simulate the operating behavior of an electrolysis device (10), characterized in that, The electrolysis device (10) is designed as an electrolysis device according to any one of claims 1 to 8, and the contour body (37) of the measuring chamber (30) ensures the uniformity of temperature distribution in the measuring chamber (30), and calculates the effect of impurities on the velocity of sound (42) in the mixed gas (11) while ignoring interference effects.

13. The simulation program product (60) according to claim 12, characterized in that, The simulation program product (60) is designed as a digital twin of the electrolysis device (10).

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