Method and device for selectively measuring hydrogen concentration based on acoustic technology

Abstract

The invention discloses a device for selectively measuring hydrogen concentration based on an acoustic technology. The device comprises a measuring cavity module, a hydrogen concentration detection module and a hydrogen concentration detection module, wherein the measuring cavity module comprises a reference gas measuring cavity and a target gas measuring cavity; at least two pairs of ultrasonic transducers are respectively arranged in the reference gas measuring cavity and the target gas measuring cavity; the signal generation module is connected with the ultrasonic transceiving module and outputs homologous signals with different frequencies to the ultrasonic transducer; the signal processing module is connected with the ultrasonic transceiving module and is used for acquiring and processing the received ultrasonic signal to obtain the hydrogen concentration; one part of the to-be-measured gas flows through the hydrogen adsorption module and then enters the reference gas measurement cavity, and the other part of the to-be-measured gas enters the target gas measurement cavity. The invention further discloses a method corresponding to the device. The device can realize selective measurement of hydrogen and improve the measurement precision of hydrogen.

Description

Technical Field

[0001] The present invention belongs to the field of hydrogen concentration measurement, and in particular relates to a method and a device for selectively measuring hydrogen concentration based on acoustic technology. Background Art

[0002] As a pollution-free, efficient and clean energy and an important chemical raw material, hydrogen is widely used in aerospace, military, clean power generation, transportation, chemical industry and other fields. However, hydrogen is a highly diffusible and flammable gas. It is very easy to explode when the volume ratio of hydrogen in the air reaches more than 4% at normal temperature and pressure. The effective detection of hydrogen is crucial to ensure the safety of hydrogen in the industrial production process.

[0003] At present, the main types of hydrogen detectors at home and abroad are optical, electrochemical, catalytic, and semiconductor. Optical gas sensors have high accuracy, but they are too expensive and have poor environmental adaptability. They cannot work stably for a long time in harsh pollution environments. Electrochemical and catalytic sensors generally have problems such as poor long-term stability, high power consumption, and short life. Metal oxide semiconductor sensors have poor stability and linearity and high power consumption, and are not suitable for high-accuracy environmental applications.

[0004] With the development of hydrogen energy applications, the problem of how to further reduce the cost of hydrogen sensors and detect hydrogen concentration components with low cost and high accuracy needs to be further solved.

[0005] The use of acoustic technology to measure hydrogen concentration has the advantages of fast response, low cost, low power consumption, long life, good stability, and strong environmental adaptability. However, at the same time, the acoustic hydrogen detection technology has the problem of poor hydrogen selectivity, and the measurement results are easily affected by other gases, dust particles, and temperature and humidity, which reduces the detection accuracy. For example, the Chinese patent with application number CN201710633542.6 provides a method for determining the concentration and pressure of each gas in multiple gases. The principle can be summarized as measuring the concentration and pressure of the gas based on calibration. However, the invention does not consider the influence of dust particles and air humidity, and for specific gases, especially hydrogen, no effective selective measurement scheme is proposed. For example, the Chinese patent with application number CN202110251272.9 provides a hydrogen measurement system and method based on ultrasonic dual-frequency phase difference, which provides a solution to solve the problem of small hydrogen concentration detection range based on ultrasonic phase difference method, but does not propose a solution for how to improve the selectivity of hydrogen measurement and eliminate the interference of other gases, dust particles, and temperature and humidity.

[0006] Up to now, there is still a lack of effective and feasible solutions to the problem of how to eliminate the interference of other gases, dust particles, temperature and humidity, and improve the hydrogen selectivity and measurement accuracy of acoustic-based hydrogen measurement technology. Summary of the invention

[0007] The object of the present invention is to provide a method and device for selectively measuring hydrogen concentration based on acoustic technology, which can realize selective measurement of hydrogen and improve the measurement accuracy of hydrogen.

[0008] The present invention provides the following technical solutions:

[0009] A device for selectively measuring hydrogen concentration based on acoustic technology, the device comprising:

[0010] A measurement chamber module, including a reference gas measurement chamber and a target gas measurement chamber;

[0011] The ultrasonic transceiver module includes six pairs of ultrasonic transducers, three pairs of which are arranged at the same position of the reference gas measurement cavity and the target gas measurement cavity: one pair is arranged at the two ends of the reference gas measurement cavity and the target gas measurement cavity facing each other along the axis, and two pairs are arranged at the outer sides of the walls of the reference gas measurement cavity and the target gas measurement cavity facing each other in an axisymmetric position;

[0012] A hydrogen adsorption module is used to adsorb hydrogen from the gas to be tested;

[0013] A signal generating module is connected to the ultrasonic transceiver module and is used to output homologous signals of different frequencies to the three pairs of ultrasonic transducers;

[0014] The signal processing module is connected to the ultrasonic transceiver module to collect and process the received ultrasonic signal to obtain the hydrogen concentration;

[0015] A portion of the gas to be measured flows through the hydrogen adsorption module and enters the reference gas measurement chamber, and another portion of the gas to be measured enters the target gas measurement chamber.

[0016] The ultrasonic transducer comprises three pairs of ultrasonic transducers arranged at the same positions of the reference gas measurement cavity and the target gas measurement cavity: one pair is arranged at the two ends of the reference gas measurement cavity and the target gas measurement cavity facing each other along the axis, and two pairs are arranged at the outer sides of the walls of the reference gas measurement cavity and the target gas measurement cavity facing each other in an axisymmetric position; specifically:

[0017] The first ultrasonic transducer and the second ultrasonic transducer are placed at two ends of the reference gas measurement cavity facing each other along the axis, and the third ultrasonic transducer and the fourth ultrasonic transducer, and the fifth ultrasonic transducer and the sixth ultrasonic transducer are placed on the outside of the wall of the reference gas measurement cavity facing each other in an axisymmetric position;

[0018] The seventh ultrasonic transducer and the eighth ultrasonic transducer are placed at both ends of the target gas measurement cavity facing each other along the axis, and the ninth ultrasonic transducer and the tenth ultrasonic transducer, and the eleventh ultrasonic transducer and the twelfth ultrasonic transducer are placed on the outside of the wall of the target gas measurement cavity in an axially symmetrical position facing each other.

[0019] The signal generating module is connected to the first ultrasonic transducer and the seventh ultrasonic transducer, and outputs a homologous signal of frequency f1; the signal generating module is connected to the third ultrasonic transducer and the ninth ultrasonic transducer, and outputs a homologous signal of frequency f2; the signal generating module is connected to the fifth ultrasonic transducer and the eleventh ultrasonic transducer, and outputs a homologous signal of frequency f3;

[0020] The signal processing module is connected to the second ultrasonic transducer, the fourth ultrasonic transducer, the sixth ultrasonic transducer, the eighth ultrasonic transducer, the tenth ultrasonic transducer and the twelfth ultrasonic transducer.

[0021] The hydrogen adsorption module comprises an adsorption material container and a hydrogen adsorption material, wherein the hydrogen adsorption material is selected from AB5 type alloy, AB2 type alloy, AB type alloy, A2B type alloy, palladium-based material, metal hydride, carbonaceous material, coordinated hydride, gas hydrate, porous carbon material, metal organic framework compound, microporous organic polymer or zeolite.

[0022] Preferably, the device includes a dust removal and dehumidification module, including a first dust removal and dehumidifier and a second dust removal and dehumidifier, the first dust removal and dehumidifier is connected to the air inlet of the reference gas measurement chamber, and the second dust removal and dehumidifier is connected to the air inlet of the target gas measurement chamber; the portion of the gas to be measured flows through the hydrogen adsorption module and the first dust removal and dehumidifier in sequence and enters the reference gas measurement chamber.

[0023] The dust removal and dehumidification module provided by the present invention uses a particle filter and a dehumidifying agent to perform dust removal and dehumidification treatment on the gas to be tested, thereby further avoiding interference between dust particles and gas humidity.

[0024] The first dust removal and dehumidifier has the same structure as the second dust removal and dehumidifier, and includes a dust particle filter and a dehumidifier.

[0025] Preferably, the device comprises a temperature measurement module placed inside the reference gas measurement cavity and the target gas measurement cavity. The present invention measures the real-time temperature of the gas through the temperature measurement module to avoid interference caused by temperature changes.

[0026] The temperature measurement module includes a first temperature sensor and a second temperature sensor, and the first temperature sensor and the second temperature sensor are respectively disposed inside the reference gas measurement cavity and the target gas measurement cavity.

[0027] In the present invention, the reference gas measurement cavity and the target gas measurement cavity are provided with an air inlet and an air outlet at both ends, and the two cavities have the same structure and size. The reference gas measurement cavity and the target gas measurement cavity are in the shape of a column.

[0028] The signal generating module comprises a signal generator and a signal connecting line, which are connected to the ultrasonic transceiver module; the signal processing module comprises a signal processor and a signal connecting line, which are connected to the ultrasonic transceiver module, the temperature measuring module and the signal generating module.

[0029] The present invention also provides a method for selectively measuring hydrogen concentration based on acoustic technology using the above device, the method comprising the following steps:

[0030] (1) A portion of the gas to be measured flows through the hydrogen adsorption module and the first dust removal and dehumidification device in sequence and then enters the reference gas measurement chamber to form a reference measurement channel;

[0031] (2) Another part of the gas to be measured flows through the second dust removal and dehumidification device into the target gas measurement cavity to form a target measurement channel;

[0032] (3) The signal generating module sends a signal of frequency f1 to the first ultrasonic transducer and the seventh ultrasonic transducer, so that the first ultrasonic transducer and the seventh ultrasonic transducer send ultrasonic waves to the second ultrasonic transducer and the eighth ultrasonic transducer respectively, and the signal processing module obtains the sound wave attenuation coefficient α1 between the first ultrasonic transducer and the second ultrasonic transducer, and the ultrasonic phase difference between the second ultrasonic transducer in the reference measurement channel and the eighth ultrasonic transducer in the target measurement channel.

[0033] (4) The signal generating module sends a signal of frequency f2 to the third ultrasonic transducer and the ninth ultrasonic transducer, so that the third ultrasonic transducer and the ninth ultrasonic transducer send ultrasonic waves to the fourth ultrasonic transducer and the tenth ultrasonic transducer respectively. The signal processing module obtains the acoustic wave attenuation coefficient α2 between the third ultrasonic transducer and the fourth ultrasonic transducer, and the ultrasonic phase difference between the fourth ultrasonic transducer in the reference measurement channel and the tenth ultrasonic transducer in the target measurement channel.

[0034] (5) The signal generating module sends a signal of frequency f3 to the fifth ultrasonic transducer and the eleventh ultrasonic transducer, so that the fifth ultrasonic transducer and the eleventh ultrasonic transducer send ultrasonic waves to the sixth and twelfth ultrasonic transducers respectively, and the signal processing module obtains the sound wave attenuation coefficient α3 between the fifth ultrasonic transducer and the sixth ultrasonic transducer, and the ultrasonic phase difference between the sixth ultrasonic transducer in the reference measurement channel and the twelfth ultrasonic transducer in the target measurement channel.

[0035] (6) The signal processing module collects the acoustic wave attenuation coefficients α1, α2, and α3 of the reference measurement channel, and solves the volume fractions u1, u2, and u3 of each interfering gas component in the reference gas measurement cavity by using a simultaneous acoustic attenuation equation group;

[0036] (7) The signal processing module collects the ultrasonic phase difference between the reference measurement channel and the target measurement channel The simultaneous sound velocity equations are used to solve the volume fraction u0' of the hydrogen gas to be measured in the target gas measurement chamber and the volume fractions u1', u2', and u3' of each interfering gas component.

[0037] Preferably, the range of f1, f2 and f3 is 1000 Hz to 100 MHz.

[0038] The present invention utilizes the principle that the sound velocity and the sound attenuation coefficient are different in different gas media, measures the difference in the sound velocity and the sound attenuation coefficient between different gases to infer the difference in the composition of different gases, uses a material with a hydrogen selective adsorption function to adsorb and remove the hydrogen in the target gas, and then places the original target gas and the reference gas after the hydrogen selective adsorption in a cavity with the same structure: first, in a reference measurement channel, the sound attenuation coefficient of the reference gas under ultrasonic waves of different frequencies is obtained by measurement, and a group of sound attenuation equations are solved to solve the concentrations of multiple interfering gases; secondly, in a target measurement channel, multiple groups of sound velocity phase differences of homologous ultrasonic waves of different frequencies in two cavities are measured, and a group of sound velocity phase difference equations are solved, and the concentration of the hydrogen to be measured in the target gas is calculated in combination with the concentration information of the multiple interfering gases solved in the reference measurement channel, thereby realizing the selective measurement of hydrogen in the mixed gas and improving the measurement accuracy.

[0039] On the basis of realizing the selective measurement of hydrogen, the dust removal and dehumidification module in the present invention can further avoid the interference between dust particles and gas humidity. The temperature measurement module in the present invention avoids interference caused by temperature changes by monitoring the real-time temperature of the gas to be measured, thereby further improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A structural diagram of a device for selectively measuring hydrogen concentration based on acoustic technology according to an embodiment of the present invention is schematically provided;

[0041] Figure 1The serial numbers in the figure represent: 1-first ultrasonic transducer; 2-second ultrasonic transducer; 3-third ultrasonic transducer; 4-fourth ultrasonic transducer; 5-fifth ultrasonic transducer; 6-sixth ultrasonic transducer; 7-seventh ultrasonic transducer; 8-eighth ultrasonic transducer; 9-ninth ultrasonic transducer; 10-tenth ultrasonic transducer; 11-eleventh ultrasonic transducer; 12-twelfth ultrasonic transducer; 13-reference gas measurement chamber; 14-target gas measurement chamber; 15-first temperature sensor; 16-second temperature sensor; 17-first dust removal and dehumidifier; 18-second dust removal and dehumidifier; 19-hydrogen adsorption module; 20-signal processing module; 21-signal generation module;

[0042] Figure 2 This is a diagram of actual measurement signal results of measuring low-concentration hydrogen leaking into the air in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0043] The essential features and advancement of the present invention are further illustrated below by the embodiments shown in the accompanying drawings, but the present invention is by no means limited to the embodiments.

[0044] In the description of the specific embodiments, the positions or structural relationships indicated by the terms "side", "left end", "right end", "both ends", "inside", "symmetrical", "installed on", "connected" and "injected" are based on the positions or structural relationships shown in the drawings and are only for the purpose of describing the present invention. They do not mean that the present invention must have such positions or structural relationships. Moreover, the positions, sizes, shapes and structural relationships of the components in the drawings do not fully reflect the actual positions, sizes, structures and shapes of the components. They are only schematic structural diagrams and therefore cannot be understood as limitations on the present invention.

[0045] Similarly, in the specific embodiments, the terms "first", "second", etc. are only used to describe features and cannot be understood as the number of features of the invention or the priority of the invention instance. The terms "in this preferred embodiment", "embodiment", "for example", etc. are used to describe an optional but not necessary specific implementation method, rather than the invention requirements themselves.

[0046] The first embodiment of the present invention proposes a device for selectively measuring hydrogen concentration based on acoustic technology, including: a first ultrasonic transducer 1; a second ultrasonic transducer 2; a third ultrasonic transducer 3; a fourth ultrasonic transducer 4; a fifth ultrasonic transducer 5; a sixth ultrasonic transducer 6; a seventh ultrasonic transducer 7; an eighth ultrasonic transducer 8; a ninth ultrasonic transducer 9; a tenth ultrasonic transducer 10; an eleventh ultrasonic transducer 11; a twelfth ultrasonic transducer 12; a reference gas measurement cavity 13; a target gas measurement cavity 14; a first temperature sensor 15; a second temperature sensor 16; a first dust removal and dehumidifier 17; a second dust removal and dehumidifier 18; a hydrogen adsorption module 19; a signal processing module 20; and a signal generating module 21.

[0047] The reference gas measurement cavity 13 and the target gas measurement cavity 14 form a measurement cavity module, with an air inlet and an air outlet at both ends of the cavity, and the two cavities have the same structure and size;

[0048] A total of six pairs of ultrasonic transducers, including the first ultrasonic transducer 1 and the second ultrasonic transducer 2, the third ultrasonic transducer 3 and the fourth ultrasonic transducer 4, the fifth ultrasonic transducer 5 and the sixth ultrasonic transducer 6, the seventh ultrasonic transducer 7 and the eighth ultrasonic transducer 8, the ninth ultrasonic transducer 9 and the tenth ultrasonic transducer 10, and the eleventh ultrasonic transducer 11 and the twelfth ultrasonic transducer 12, constitute an ultrasonic transceiver module and are installed on the reference gas measurement cavity 13 and the target gas measurement cavity 14.

[0049] The first dust removal and dehumidifier 17 and the second dust removal and dehumidifier 18 form a dust removal and dehumidification module, the first dust removal and dehumidifier 17 is connected to the air inlet of the reference gas measurement chamber 13, and the second dust removal and dehumidifier 18 is connected to the air inlet of the target gas measurement chamber 14;

[0050] The hydrogen adsorption module 19 includes an adsorption material container and hydrogen adsorption material, and is connected to the first dust removal and dehumidification device 17;

[0051] The first temperature sensor 15 and the second temperature sensor 16 constitute a temperature measurement module, and the first temperature sensor 15 and the second temperature sensor 16 are respectively placed inside the reference gas measurement cavity 13 and the target gas measurement cavity 14;

[0052] The signal generating module 21 includes a signal generator and a signal connecting line, and is connected to the first ultrasonic transducer 1, the third ultrasonic transducer 3, the fifth ultrasonic transducer 5, the seventh ultrasonic transducer 7, the ninth ultrasonic transducer 9, and the eleventh ultrasonic transducer 11;

[0053] The signal processing module 20 includes a signal processor and a signal connection line, and is connected to the second ultrasonic transducer 2, the fourth ultrasonic transducer 4, the sixth ultrasonic transducer 6, the eighth ultrasonic transducer 8, the tenth ultrasonic transducer 10, the twelfth ultrasonic transducer 12, the first temperature sensor 15, the second temperature sensor 16, and the signal generating module 21.

[0054] In this preferred embodiment, the reference gas measurement chamber 13 and the target gas measurement chamber 14 are in the shape of columns.

[0055] In this preferred embodiment, the gas to be measured flows through the hydrogen adsorption module 19 and the first dust removal and dehumidification device 17 in sequence, and enters the reference gas measurement cavity 13 from the air inlet to form a reference measurement channel.

[0056] In this preferred embodiment, the gas to be measured flows through the second dust removal and dehumidification device 18 and enters the target gas measurement cavity 14 from the air inlet to form a target measurement channel.

[0057] In this preferred embodiment, the first ultrasonic transducer 1 and the second ultrasonic transducer 2 are placed at the two ends of the reference gas measurement cavity 13 facing each other along the axis; the seventh ultrasonic transducer 7 and the eighth ultrasonic transducer 8 are placed at the two ends of the target gas measurement cavity 14 facing each other along the axis; the third ultrasonic transducer 3 and the fourth ultrasonic transducer 4, the fifth ultrasonic transducer 5 and the sixth ultrasonic transducer 6 are placed on the wall of the reference gas measurement cavity 13 in an axially symmetrical position facing each other; the ninth ultrasonic transducer 9 and the tenth ultrasonic transducer 10, the eleventh ultrasonic transducer 11 and the twelfth ultrasonic transducer 12 are placed on the wall of the target gas measurement cavity 14 in an axially symmetrical position facing each other.

[0058] In this preferred embodiment, the signal generating module 21 is connected to the first ultrasonic transducer 1 and the seventh ultrasonic transducer 7, and outputs a homologous signal of frequency f1; the signal generating module 21 is connected to the third ultrasonic transducer 3 and the ninth ultrasonic transducer 9, and outputs a homologous signal of frequency f2; the signal generating module 21 is connected to the fifth ultrasonic transducer 5 and the eleventh ultrasonic transducer 11, and outputs a homologous signal of frequency f3.

[0059] In this preferred embodiment, the signal processing module 20 is connected to the second ultrasonic transducer 2, the fourth ultrasonic transducer 4, the sixth ultrasonic transducer 6, the eighth ultrasonic transducer 8, the tenth ultrasonic transducer 10, and the twelfth ultrasonic transducer 12 to collect and process signals.

[0060] In this preferred embodiment, the first dust removal and dehumidifier 17 and the second dust removal and dehumidifier 18 have the same specific structure, including a dust particle filter and a dehumidifier.

[0061] The second embodiment of the present invention proposes a method for selectively measuring hydrogen concentration based on acoustic technology, the steps comprising:

[0062] (1) The gas to be tested is selectively adsorbed and removed by the hydrogen adsorption module 19, and then filtered and removed by the first dust removal and dehumidification device 17 to remove the particulate matter and water vapor therein, and then injected into the reference gas measurement chamber 13;

[0063] (2) The gas to be measured is filtered and dehumidified by the second dust removal device 18 to remove particulate matter and water vapor therein, and then injected into the target gas measurement cavity 14;

[0064] (3) The signal generating module 21 sends a signal of frequency f1 to the first ultrasonic transducer 1 and the seventh ultrasonic transducer 7, so that the first ultrasonic transducer 1 and the seventh ultrasonic transducer 7 send ultrasonic waves to the second ultrasonic transducer 2 and the eighth ultrasonic transducer 8 respectively, and the signal processing module 20 obtains the acoustic wave attenuation coefficient α1 between the first ultrasonic transducer 1 and the second ultrasonic transducer 2, and the ultrasonic phase difference between the second ultrasonic transducer 2 in the reference measurement channel and the eighth ultrasonic transducer 8 in the target measurement channel.

[0065] (4) The signal generating module 21 sends a signal of frequency f2 to the third ultrasonic transducer 3 and the ninth ultrasonic transducer 9, so that the third ultrasonic transducer 3 and the ninth ultrasonic transducer 9 send ultrasonic waves to the fourth ultrasonic transducer 4 and the tenth ultrasonic transducer 10 respectively, and the signal processing module 20 obtains the sound wave attenuation coefficient α2 between the third ultrasonic transducer 3 and the fourth ultrasonic transducer 4, and the ultrasonic phase difference between the fourth ultrasonic transducer 4 in the reference measurement channel and the tenth ultrasonic transducer 10 in the target measurement channel.

[0066] (5) The signal generating module 21 sends a signal of frequency f3 to the fifth ultrasonic transducer 5 and the eleventh ultrasonic transducer 11, so that the fifth ultrasonic transducer 5 and the eleventh ultrasonic transducer 11 send ultrasonic waves to the sixth ultrasonic transducer 6 and the twelfth ultrasonic transducer 12 respectively, and the signal processing module 20 obtains the acoustic wave attenuation coefficient α3 between the fifth ultrasonic transducer 5 and the sixth ultrasonic transducer 6, and the ultrasonic phase difference between the sixth ultrasonic transducer 6 in the reference measurement channel and the twelfth ultrasonic transducer 12 in the target measurement channel.

[0067] (6) The first temperature sensor 15 and the second temperature sensor 16 transmit the gas temperature information in the reference gas measurement chamber 13 and the target gas measurement chamber 14 to the signal processing module 20, and the signal processing module 20 obtains the gas temperatures T and T' in the reference measurement channel and the target measurement channel;

[0068] (7) The volume fractions u1, u2, and u3 of the interfering gas components in the reference gas measurement chamber 13 are solved according to the equation group (1);

[0069]

[0070] Where, the subscript i represents the i-th interfering gas, c is the gas sound velocity, M is the gas relative molecular mass, R is the universal gas constant, f is the sound wave frequency, ω is the sound wave angular frequency, and γ = C p / C v is the specific heat ratio, C p is the constant pressure specific heat of gas molecules, C v is the constant volume specific heat of gas molecules, μ' is the gas viscosity coefficient, k is the thermal conductivity, p0 and ρ0 are the gas static pressure and density respectively, C v0 With C v∞ are the specific heat of gas at constant volume under extremely high frequency excitation and without excitation, respectively, and τ is the gas relaxation time; among them, when calculating the gas sound velocity, the calculation is performed based on the temperature T of the reference measurement channel, which has a certain effect on temperature compensation;

[0071] Solve equation group (1) to calculate the volume fractions u1, u2, and u3 of each interfering gas component in the reference gas;

[0072] (8) The volume fraction u0' of the hydrogen gas to be measured in the target gas measurement chamber 14 and the volume fractions u1', u2', and u3' of each interfering gas component are solved according to equation group (2);

[0073]

[0074] Wherein, L is the length of the reference gas measurement cavity 13 and the target gas measurement cavity 14, and D is the diameter of the reference gas measurement cavity 13 and the target gas measurement cavity 14; wherein, when calculating the gas sound velocity, the calculation is performed according to the temperature T' of the target measurement channel, which has a certain effect on temperature compensation.

[0075] Solve equation group (2) to calculate the hydrogen gas volume fraction u0' to be measured in the target gas.

[0076] In the preferred embodiment, the frequencies f1, f2 and f3 range from 1000 Hz to 100 MHz.

[0077] Figure 2 This is a diagram showing the actual measurement signal result of measuring low-concentration hydrogen leaking into the air in this embodiment. Figure 2 It can be seen that the ultrasonic phase and amplitude attenuation signals of different target gases measured by the present invention vary significantly, and the measurement signals of trace hydrogen leaks of different concentrations are quite different, which can effectively detect hydrogen in mixed gases with a concentration as low as 100 ppm.

[0078] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A device for selectively measuring hydrogen concentration based on acoustic technology, characterized in that: The device comprises: A measurement chamber module, including a reference gas measurement chamber and a target gas measurement chamber; The ultrasonic transceiver module has at least two pairs of ultrasonic transducers arranged in the reference gas measurement cavity and the target gas measurement cavity respectively; A hydrogen adsorption module is used to adsorb hydrogen from the gas to be tested; A signal generating module is connected to the ultrasonic transceiver module and is used to output homologous signals of different frequencies to the ultrasonic transducer; The signal processing module is connected to the ultrasonic transceiver module to collect and process the received ultrasonic signal to obtain the hydrogen concentration; A portion of the gas to be measured flows through the hydrogen adsorption module and enters the reference gas measurement chamber, and another portion of the gas to be measured enters the target gas measurement chamber.

2. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 1, characterized in that: The ultrasonic transducer comprises three pairs of ultrasonic transducers arranged at the same positions of the reference gas measurement cavity and the target gas measurement cavity: one pair is arranged at the two ends of the reference gas measurement cavity and the target gas measurement cavity facing each other along the axis, and two pairs are arranged at the outer sides of the walls of the reference gas measurement cavity and the target gas measurement cavity facing each other in an axisymmetric position; specifically: The first ultrasonic transducer and the second ultrasonic transducer are placed at two ends of the reference gas measurement cavity facing each other along the axis, and the third ultrasonic transducer and the fourth ultrasonic transducer, and the fifth ultrasonic transducer and the sixth ultrasonic transducer are placed on the outside of the wall of the reference gas measurement cavity facing each other in an axisymmetric position; The seventh ultrasonic transducer and the eighth ultrasonic transducer are placed at both ends of the target gas measurement cavity facing each other along the axis, and the ninth ultrasonic transducer and the tenth ultrasonic transducer, and the eleventh ultrasonic transducer and the twelfth ultrasonic transducer are placed on the outside of the wall of the target gas measurement cavity in an axially symmetrical position facing each other.

3. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 2, characterized in that: The signal generating module is connected to the first ultrasonic transducer and the seventh ultrasonic transducer, and outputs a homologous signal of frequency f1; the signal generating module is connected to the third ultrasonic transducer and the ninth ultrasonic transducer, and outputs a homologous signal of frequency f2; the signal generating module is connected to the fifth ultrasonic transducer and the eleventh ultrasonic transducer, and outputs a homologous signal of frequency f3; The signal processing module is connected to the second ultrasonic transducer, the fourth ultrasonic transducer, the sixth ultrasonic transducer, the eighth ultrasonic transducer, the tenth ultrasonic transducer and the twelfth ultrasonic transducer.

4. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 1, characterized in that: The hydrogen adsorption module comprises an adsorption material container and a hydrogen adsorption material, wherein the hydrogen adsorption material is selected from AB5 type alloy, AB2 type alloy, AB type alloy, A2B type alloy, palladium-based material, metal hydride, carbonaceous material, coordinated hydride, gas hydrate, porous carbon material, metal organic framework compound, microporous organic polymer or zeolite.

5. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 1, characterized in that: The device includes a dust removal and dehumidification module, including a first dust removal and dehumidifier and a second dust removal and dehumidifier, the first dust removal and dehumidifier is connected to the air inlet of the reference gas measurement chamber, and the second dust removal and dehumidifier is connected to the air inlet of the target gas measurement chamber; the part of the gas to be measured flows through the hydrogen adsorption module and the first dust removal and dehumidifier in sequence and enters the reference gas measurement chamber.

6. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 5, characterized in that: The first dust removal and dehumidifier has the same structure as the second dust removal and dehumidifier, and includes a dust particle filter and a dehumidifier.

7. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 1, characterized in that: The device comprises temperature measurement modules disposed inside the reference gas measurement cavity and the target gas measurement cavity.

8. The device for selectively measuring hydrogen concentration based on acoustic technology according to claim 7, characterized in that: The temperature measurement module includes a first temperature sensor and a second temperature sensor, and the first temperature sensor and the second temperature sensor are respectively disposed inside the reference gas measurement cavity and the target gas measurement cavity.

9. A method for selectively measuring hydrogen concentration based on acoustic technology using the device according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: (1) A portion of the gas to be measured flows through the hydrogen adsorption module and the first dust removal and dehumidification device in sequence and then enters the reference gas measurement chamber to form a reference measurement channel; (2) Another part of the gas to be measured flows through the second dust removal and dehumidification device into the target gas measurement cavity to form a target measurement channel; (3) The signal generating module sends a signal of frequency f1 to the first ultrasonic transducer and the seventh ultrasonic transducer, so that the first ultrasonic transducer and the seventh ultrasonic transducer send ultrasonic waves to the second ultrasonic transducer and the eighth ultrasonic transducer respectively, and the signal processing module obtains the sound wave attenuation coefficient α1 between the first ultrasonic transducer and the second ultrasonic transducer, and the ultrasonic phase difference between the second ultrasonic transducer in the reference measurement channel and the eighth ultrasonic transducer in the target measurement channel. (4) The signal generating module sends a signal of frequency f2 to the third ultrasonic transducer and the ninth ultrasonic transducer, so that the third ultrasonic transducer and the ninth ultrasonic transducer send ultrasonic waves to the fourth ultrasonic transducer and the tenth ultrasonic transducer respectively, and the signal processing module obtains the sound wave attenuation coefficient α2 between the third ultrasonic transducer and the fourth ultrasonic transducer, and the ultrasonic phase difference between the fourth ultrasonic transducer in the reference measurement channel and the tenth ultrasonic transducer in the target measurement channel. (5) The signal generating module sends a signal of frequency f3 to the fifth ultrasonic transducer and the eleventh ultrasonic transducer, so that the fifth ultrasonic transducer and the eleventh ultrasonic transducer send ultrasonic waves to the sixth and twelfth ultrasonic transducers respectively, and the signal processing module obtains the acoustic wave attenuation coefficient α3 between the fifth ultrasonic transducer and the sixth ultrasonic transducer, and the ultrasonic phase difference between the sixth ultrasonic transducer in the reference measurement channel and the twelfth ultrasonic transducer in the target measurement channel. (6) The signal processing module collects the acoustic wave attenuation coefficients α1, α2, and α3 of the reference measurement channel, and solves the volume fractions u1, u2, and u3 of each interfering gas component in the reference gas measurement cavity by using a simultaneous acoustic attenuation equation group; (7) The signal processing module collects the ultrasonic phase difference between the reference measurement channel and the target measurement channel The simultaneous sound velocity equations are used to solve the hydrogen gas volume fraction u0 in the target gas measurement chamber. ’ , and the volume fraction u1 of each interfering gas component ’ 、u2 ’ 、u3 ’ .

10. The device according to claim 9, characterized in that The range of f1, f2 and f3 is 1000 Hz to 100 MHz.

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