Leakage detection system and leakage detection method for gas-liquid two-phase working medium

Abstract

The application relates to the technical field of spacecraft leakage detection, in particular to a leakage rate detection system and method for gas-liquid two-phase working medium, the leakage rate detection system comprising a vacuum container, a gas sensor and a control device, wherein the gas sensor is arranged in the vacuum container, the gas sensor comprises a gas-sensitive element for adsorbing leakage gas of a to-be-detected product and changing the resistance value of the gas sensor and a detection element for collecting the current value of the gas sensor; and the control device calculates the leakage rate of the leakage gas of the to-be-detected product. In the application, the leakage rate detection system adsorbs the leakage gas of the to-be-detected product through the gas sensor, and the leakage rate of the leakage gas of the to-be-detected product is calculated, so that the leakage rate detection method is simplified, the shortcomings of the precision and sensitivity of the actual working medium leakage detection are made up, accurate quantitative analysis is realized, the cost of the spacecraft development stage is reduced, and the efficiency and reliability of the gas-liquid two-phase working medium leakage detection are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spacecraft leak detection, and in particular to a leak rate detection system and method for gas-liquid two-phase working medium. BACKGROUND

[0002] The development process of space products involves a large number of components, parts and whole machine products with sealing performance requirements, such as heat pipes of thermal control systems, storage tanks of propellant fuels and sealed cabins of manned spacecraft, etc. As one of the extremely important technical indicators in spacecraft structure reliability, the sealing performance of space products is directly related to the launch success rate and on-orbit service life of spacecraft. Therefore, in order to ensure high reliability of spacecraft, leak detection is throughout the whole life cycle of space products from design, single machine manufacturing, assembly, whole machine delivery, launch to operation, and it is an important means to ensure the sealing performance of space products.

[0003] For some single machine products of spacecraft, such as cold plates, phase change plates and heat pipes of thermal control systems, etc., heat transfer working medium such as ammonia, difluoromonochloromethane and perfluorotriethylamine is generally packaged inside, which has high sealing performance requirements and needs to detect the actual working medium for leakage. At present, four-pole mass spectrometry leak detection method, test paper method or weighing method are usually used for leak detection, but the four-pole mass spectrometry leak detection method is complex, has many factors affecting test accuracy and reliability, and is difficult to quantitatively calibrate on site; the weighing method has large detection error, low positioning accuracy and is greatly affected by environmental factors; the test paper method cannot be quantified.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The present application provides a leak rate detection system for gas-liquid two-phase working medium to solve the problem of how to improve the sensitivity and positioning accuracy of the leak rate detection system, simplify the leak rate detection method of the leak rate detection system, and reduce the error of the leak rate detection system.

[0006] In one aspect, the present application provides a leak rate detection system for gas-liquid two-phase working medium, comprising:

[0007] a vacuum container for accommodating a product to be tested;

[0008] a gas sensor arranged in the vacuum container, the gas sensor comprising a gas sensitive element for adsorbing the leaked gas of the product to be tested and changing the resistance value of the gas sensor, and a detection element for collecting the current value through the gas sensor;

[0009] a control device for calculating the leak rate of the leaked gas of the product to be tested based on the collected current value through the gas sensor.

[0010] In some embodiments, the gas sensor further comprises a data processing element for obtaining the gas concentration value in the vacuum container based on the collected current value through the gas sensor, and the control device is further configured to calculate the leak rate of the product to be tested based on the obtained gas concentration value in the vacuum container.

[0011] In some embodiments, the gas sensitive element comprises:

[0012] A two-dimensional phase change material substrate, the two-dimensional phase change material surface has a plurality of etched slits, and the plurality of slits are arranged at intervals.

[0013] A plurality of noble metal particle strips, the noble metal strips are formed by noble metal particles arranged in each of the slits.

[0014] In some embodiments, the two-dimensional phase change material substrate is formed by a transition metal sulfide; and / or

[0015] The noble metal particles are at least one of Pd, Au, and Ag.

[0016] In some embodiments, the gas sensor is provided with a heating device, and the heating device is configured to heat the gas sensitive element to periodically regenerate and restore the gas adsorption capacity of the gas sensitive element.

[0017] In another aspect, the present application also provides a leak rate detection method for a leak rate detection system of a gas-liquid two-phase working medium, comprising the following steps:

[0018] Placing the product to be tested into the vacuum container, and collecting the current value through the gas sensor in real time;

[0019] Calculating the leak rate of the product to be tested based on the collected current value through the gas sensor.

[0020] In some embodiments, the calculation of the leak rate of the product to be tested based on the collected current value through the gas sensor specifically comprises:

[0021] Obtaining the gas concentration value in the vacuum container based on the collected current value through the gas sensor;

[0022] Calculating the leak rate of the product to be tested based on the obtained gas concentration value in the vacuum container.

[0023] In some embodiments, the method comprises the following steps:

[0024] Step S1: placing the product to be tested into the vacuum container;

[0025] Step S2: obtaining a change amount AI of the gas concentration value;

[0026] Step S3: introducing a standard leak hole with a known leak rate Q0, obtaining a gas concentration change AI1, and calculating the leak rate Q through the following formula (1);

[0027] (1).

[0028] In some embodiments, when the leak rate of the to-be-tested product is greater than the response setting value, an alarm signal is sent.

[0029] In some embodiments, after the leak rate detection of the to-be-tested product is completed, the gas sensor is heated to periodically regenerate and restore the gas adsorption capacity of the gas sensitive element.

[0030] Compared with the prior art, the technical scheme has the following beneficial effects.

[0031] 1. The leak rate detection system for gas-liquid two-phase working medium in the present application simplifies the leak rate detection method, makes up for the shortcomings of precision and sensitivity in actual working medium leak detection, realizes accurate quantitative analysis, reduces the cost of spacecraft development stage, and improves the efficiency and reliability of gas-liquid two-phase working medium leak detection.

[0032] 2. The leak rate detection method of the leak rate detection system for gas-liquid two-phase working medium in the present application has all the advantages of the leak rate detection system. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a structural schematic diagram of the leak rate detection system in the embodiment of the present application;

[0034] Figure 2 is a structural schematic diagram of the gas sensitive unit in the embodiment of the present application;

[0035] Figure 3 is a schematic diagram of the leak rate detection system detecting the to-be-tested product in the embodiment of the present application;

[0036] Figure 4 is a schematic diagram of the leak rate detection system detecting the gas-liquid two-phase working medium in the embodiment of the present application;

[0037] Figure 5 is a flowchart of the leak rate detection method of the leak rate detection system in the embodiment of the present application.

[0038] In the figure: 100, leak rate detection system; 110, gas sensor; 111, gas sensitive element; 1111, two-dimensional phase change material substrate; 1112, noble metal particle strip; 11121, noble metal particle; 1113, band gap; 112, shell; 120, vacuum container; 130, display device; 200, product to be tested; 210, leak point; 300, gas-liquid two-phase working medium. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be described below in conjunction with embodiments. Obviously, the described embodiments are only part of, rather than all of, the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0040] In one aspect, the present application provides a leak rate detection system 100 for a gas-liquid two-phase working medium 300, which is used for detecting the sealing performance of a space product. The specific structure of the leak rate detection system 100 is described in detail with reference to Figures 1 to 4 which comprises a vacuum container 120, a gas sensor 110 and a control device. The gas sensor 110 is arranged in the vacuum container 120. The gas sensor 110 comprises a gas sensitive element 111 and a detection element. The gas sensitive element 111 is used for adsorbing the leaked gas of the product to be tested 200 and changing the resistance value of the gas sensor 110. The detection element is used for collecting the current value through the gas sensor 110 in real time. The control device is used for calculating the leak rate of the leaked gas of the product to be tested 200 based on the collected current value through the gas sensor 110.

[0041] The leak rate detection system 100 for the gas-liquid two-phase working medium 300 in the present application adsorbs the leaked gas of the product to be tested 200 through the gas sensor 110 and calculates the leak rate of the leaked gas of the product to be tested 200, which simplifies the leak rate detection method, makes up for the shortcomings of the accuracy and sensitivity of the actual working medium leak detection, realizes accurate quantitative analysis, reduces the cost of the spacecraft development stage, and improves the efficiency and reliability of the gas-liquid two-phase working medium 300 leak detection.

[0042] As an embodiment not shown, the gas sensor 110 further comprises a data processing element for obtaining the gas concentration value in the vacuum container 120 based on the collected current value through the gas sensor 110, so as to obtain the gas concentration value in the vacuum container 120 in real time. The control device is further used for calculating the leak rate of the leaked gas of the product to be tested 200 based on the obtained gas concentration value in the vacuum container 120. By obtaining the change amount of the gas concentration value in the vacuum container 120, the leak rate of the leaked gas of the product to be tested 200 is calculated. This leak rate detection method is simple, has small leak rate detection error, and has high detection sensitivity and positioning accuracy.

[0043] Exemplarily, the gas sensor 110 is in a state of resistance value before the detection stage starts, and the gas sensor 110 is in a state of resistance change after the detection stage starts. The gas sensitive element 111 captures gas molecules, and the resistance of the gas sensor 110 changes. The voltage applied to the gas sensor 110 does not change, and the current changes with the change of the resistance. That is, the change of the gas concentration value in the vacuum container 120 is determined by the current value.

[0044] As shown in Figure 1 , Figure 3 and Figure 4 , the gas sensor 110 includes a shell 112 having a mesh structure, and a micro data processing device and a gas sensitive element 111 disposed on the micro data processing device are encapsulated in the shell 112. The micro data processing device includes a PCB board, a signal processing circuit, an analog-to-digital conversion module, a wireless transmission module and an antenna. Exemplarily, the signal processing circuit, the analog-to-digital conversion module, the wireless transmission module and the antenna are sequentially welded on the PCB board. The signal processing circuit is configured as a detection element, the analog-to-digital conversion module is configured as a data processing element, and the wireless transmission module is in communication connection with the control device, so that the control device can receive the current value through the gas sensor 110 collected by the detection element and / or the gas concentration value in the vacuum container 120 obtained by the data processing element.

[0045] The specific structure of the gas sensitive element 111 can be referred to Figures 1 to 3 , which includes a two-dimensional phase change material substrate 1111 and a plurality of noble metal particle strips 1112. The two-dimensional phase change material surface has a plurality of etched slits, and the plurality of slits are arranged at intervals. The noble metal strip is a strip formed by noble metal particles 11121 decorated into each slit. The noble metal particle strip 1112 grown in the band gap 1113 on the two-dimensional phase change material substrate 1111. Due to the adjustability of the size and shape of the band gap 1113 and the selection of the type of noble metal, the lattice vacancies on the formed gas sensitive element 111 can only allow specific gas molecules to occupy, which affects the electrical properties of the two-dimensional phase change material.

[0046] Exemplarily, on the two-dimensional phase change material substrate 1111, a certain size of band gap 1113 is uniformly constructed by a superfast laser collaborative manufacturing method. On the band gap 1113 constructed on the two-dimensional phase change material substrate 1111, a certain form of noble metal particle 11121 column is grown in the band gap 1113 by additive-subtractive method, and the performance of the room temperature or even low temperature gas sensitive material is more excellent through surface regulation, modification and second phase complex.

[0047] As an embodiment not shown, the two-dimensional phase change material substrate 1111 is a substrate formed of a transition metal sulfide, and the noble metal particles 11121 are at least one of Pd, Au, and Ag, which can more accurately capture the gas molecules leaked from the product 200 to be measured.

[0048] As an embodiment not shown, the gas sensor 110 is provided with a heating device for heating the gas-sensitive element 111 to periodically regenerate and restore the gas adsorption capacity of the gas-sensitive element 111. After the gas sensor 110 completes the leak detection of the gas-liquid two-phase working medium 300, the gas sensor 110 is heated to facilitate the rapid regeneration of the gas sensor 110 and achieve repeated use.

[0049] As shown in Figure 1 , Figure 3 and Figure 4 , the leak detection system 100 further includes a display device 130 connected to the control device and the gas sensor 110, for displaying the gas concentration value in the vacuum container 120 and / or the leak rate of the leaked gas of the product 200 to be measured. When the leak rate of the leaked gas of the product 200 to be measured is greater than the response set value, the display device 130 sends an alarm signal.

[0050] On the other hand, as shown in Figures 1 to 5 , the application also provides a preparation method of the leak detection system 100 for the gas-liquid two-phase working medium 300, including the following steps: placing the product to be measured in the vacuum container 120, and collecting the current value through the gas sensor 110 in real time; calculating the leak rate of the leaked gas of the product 200 to be measured based on the collected current value through the gas sensor 110.

[0051] The leak detection method of the leak detection system 100 for the gas-liquid two-phase working medium 300 in the application is simple, which adsorbs the leaked gas of the product 200 to be measured by the gas sensor 110 and calculates the leak rate of the leaked gas of the product 200 to be measured. The leak detection method is simple, the error is small, the sensitivity and positioning accuracy are high, the cost of the spacecraft development stage is reduced, and the efficiency and reliability of the leak detection of the gas-liquid two-phase working medium 300 are improved.

[0052] As shown in Figure 5As shown, in this embodiment, calculating the leakage rate of the leaked gas in the product under test 200 based on the current value collected through the gas sensor 110 specifically includes: obtaining the gas concentration value inside the vacuum container 120 based on the current value collected through the gas sensor 110; calculating the leakage rate of the leaked gas in the product under test 200 based on the obtained gas concentration value inside the vacuum container 120. The gas sensitive element 111 captures gas molecules, and thus the resistance of the gas sensor 110 changes. During the detection stage, the gas sensitive element 111 captures the leaked gas molecules in the product under test 200, and its own resistance value changes. The voltage applied to it remains unchanged, and the current changes with the change in resistance, thereby determining the change in the gas concentration value inside the vacuum container 120.

[0053] In this embodiment, the leak rate detection method specifically includes the following steps:

[0054] Step S1: Place the product to be tested into the vacuum container 120;

[0055] Step S2: Obtain the change in gas concentration value ΔI;

[0056] Step S3: Introduce a standard leak with a known leak rate Q0, obtain the gas concentration change as ΔI1, and calculate the leak rate Q using the following formula (1);

[0057] (1).

[0058] In this embodiment, when the leakage rate of the leaked gas in the test product 200 is greater than the response set value, an alarm signal is issued and the gas concentration value in the vacuum container 120 is displayed at the same time.

[0059] In this embodiment, after the leak rate detection of the leaked gas of the product under test 200 is completed, the gas sensor 110 is heated to regenerate periodically and restore the gas adsorption capacity of the gas sensitive element 111.

[0060] like Figure 1 , Figures 3 to 5 As shown, when the gas sensor 110 is used to detect leaks in the product under test 200, if there is a leak point 210 in the product under test 200, the gaseous working fluid leaking from the product under test 200 can be captured by the gas sensor 110, thereby changing the electrical performance of the gas sensing element 111. The control device can convert the electrical signal measured by the gas sensor 110 into the leak rate of the product under test. The gas sensor 110 completes the leak detection of the tested product. The reaction value of the gas sensor 110 is related to the time it takes for the leaking gas from the leak point 210 of the tested product 200 to reach the gas sensor 110. The reaction value of the gas sensor 110 is large for long-term and continuous leaks.

[0061] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0062] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0063] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0064] In this application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the application. In this specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0065] Although the embodiments of the application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be understood as a limitation of the application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the application.

Claims

1. A leak rate detection system for a gas-liquid two-phase working fluid, characterized in that, include: Vacuum container, used to hold the product to be tested; A gas sensor is disposed inside the vacuum container. The gas sensor includes a gas-sensitive element for adsorbing leaked gas from the product under test and changing the resistance value of the gas sensor, and a detection element for collecting the current value passing through the gas sensor. A control device for calculating the leakage rate of the leaked gas in the product under test based on the current value collected through the gas sensor; The gas sensing element includes: A two-dimensional phase change material substrate, wherein the surface of the two-dimensional phase change material has etched slits, and a plurality of the slits are arranged at intervals, and the two-dimensional phase change material substrate is a substrate formed of transition metal sulfides; Multiple precious metal particle strips, wherein the precious metal particle strips are strips formed by modifying each of the slits with precious metal particles; The tunability of the bandgap size and shape, along with the availability of noble metals, allows specific gas molecules to occupy the lattice vacancies on the formed gas-sensitive element.

2. The leak rate detection system for gas-liquid two-phase working fluid according to claim 1, characterized in that, The gas sensor also includes a data processing element for obtaining the gas concentration value inside the vacuum container based on the current value collected through the gas sensor. The control device is also used to calculate the leakage rate of the leaking gas of the product under test based on the obtained gas concentration value inside the vacuum container.

3. The leak rate detection system for gas-liquid two-phase working fluid according to claim 1, characterized in that, The noble metal particles are at least one of Pd, Au, and Ag.

4. The leak rate detection system for gas-liquid two-phase working fluid according to any one of claims 1 to 3, characterized in that, The gas sensor is equipped with a heating device, which is used to heat the gas-sensitive element to periodically regenerate it and restore the gas adsorption capacity of the gas-sensitive element.

5. A leak rate detection method for a leak rate detection system for a gas-liquid two-phase working fluid as described in any one of claims 1 to 4, characterized in that, Including the following: The product to be tested is placed inside the vacuum container, and the current value passing through the gas sensor is collected in real time. The leakage rate of the leaked gas in the product under test is calculated based on the current value obtained through the gas sensor. Includes the following steps: Step S1: Place the product to be tested into the vacuum container; Step S2: Obtain the change in gas concentration value ΔI; Step S3: Introduce a standard leak with a known leak rate Q0, obtain the gas concentration change as ΔI1, and calculate the leak rate Q using the following formula (1); （1）。 6. The leak rate detection method for a leak rate detection system for a gas-liquid two-phase working fluid according to claim 5, characterized in that, The calculation of the leakage rate of the leaked gas in the product under test based on the current value obtained through the gas sensor specifically includes: The gas concentration value inside the vacuum container is obtained based on the current value collected through the gas sensor; The leakage rate of the leaking gas in the test product is calculated based on the obtained gas concentration value inside the vacuum container.

7. The leak rate detection method for a leak rate detection system for a gas-liquid two-phase working fluid according to claim 5 or 6, characterized in that, An alarm signal is issued when the leakage rate of the gas leaking from the product under test exceeds the response set value.

8. The leak rate detection method for a leak rate detection system for a gas-liquid two-phase working fluid according to claim 5 or 6, characterized in that, After the leak rate detection of the leaked gas in the product under test is completed, the gas sensor is heated to regenerate it periodically and restore the gas adsorption capacity of the gas sensing element.

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