Calibrating device for gas flow meter

Abstract

The utility model provides a gas flow meter calibration device, which comprises a circulation pipeline, a gas flow meter calibration device, a gas flow meter calibration device, a gas flow meter calibration device and a gas flow meter calibration device, and is characterized in that the circulation pipeline is provided with a gas inlet and a gas outlet which are oppositely arranged; the flow detection assembly is arranged on the circulation pipeline, the flow detection assembly is used for detecting the flow of gas in the circulation pipeline, and the flowmeter to be calibrated is arranged on the circulation pipeline and located on the downstream of the flow detection assembly; the monitoring assembly is arranged on the circulation pipeline, the monitoring assembly comprises a humidity monitoring assembly and a concentration monitoring assembly, and the humidity monitoring assembly is located on the upstream of the concentration monitoring assembly and the flow detection assembly. According to the technical scheme provided by the utility model, the problem of low accuracy of the calibration result of the calibration device in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of flow meter detection, in particular to a gas flow meter calibration device. Background Art

[0002] With the development of the hydrogen energy industry, hydrogen flowmeters are widely used in hydrogen transportation, hydrogen energy storage, and hydrogen industry. Taking hydrogen transportation as an example, hydrogen fuel cell vehicles are expected to become an important development direction for future new energy vehicles. As an important component of the onboard hydrogen supply system of hydrogen fuel cell vehicles, the reliability of hydrogen flowmeters plays an important role in the normal operation of the fuel cell system. According to the relevant regulations of the Metrology Department of the State Administration for Market Regulation, the flowmeters used in the equipment should be calibrated regularly during use to ensure their reliability. In the actual calibration process, a gas flow device based on the critical flow Venturi nozzle method is generally used for calibration.

[0003] Patent CN214667159U describes a mobile gas flow calibration device controlled by a host computer. However, this device is unable to dry the gas being tested or analyze its concentration during operation, thus failing to guarantee the purity of the gas source. During gas flow calibration, the humidity of the gas being tested significantly affects the accuracy of the calibration results. Furthermore, existing online hydrogen flow meter calibration devices cannot analyze the gas concentration in the pipeline containing the flow meter being tested in real time, thus affecting the accuracy of the calibration results. Utility Model Content

[0004] The utility model provides a gas flow meter calibration device to solve the problem of low accuracy of calibration results of calibration devices in the prior art.

[0005] The utility model provides a gas flow meter calibration device, which includes: a circulation pipeline, which has an air inlet and an air outlet arranged relatively to each other, and the air inlet is connected to a gas source; a flow detection component, which is arranged on the circulation pipeline, and the flow detection component is used to detect the flow of gas in the circulation pipeline, and the flow meter to be calibrated is arranged on the circulation pipeline and is located downstream of the flow detection component; a monitoring component, which is arranged on the circulation pipeline, and the monitoring component includes a humidity monitoring component and a concentration monitoring component, and the humidity monitoring component is located upstream of the concentration monitoring component and the flow detection component.

[0006] Furthermore, the concentration monitoring component includes: a concentration monitoring pipeline, which is connected to the circulation pipeline, and the connection between the concentration monitoring pipeline and the circulation pipeline is located between the humidity monitoring component and the flow detection component; a concentration sensor, which is arranged on the concentration monitoring pipeline, and has an exhaust port on the concentration monitoring pipeline, and the exhaust port is located downstream of the concentration sensor, and the exhaust port is used to discharge the fluid in the concentration monitoring pipeline; a first control valve, which is arranged on the concentration monitoring pipeline and is located upstream of the concentration sensor.

[0007] Furthermore, the exhaust port is communicated with the air outlet.

[0008] Furthermore, the humidity monitoring component includes a humidity sensor, a second control valve, a drying pipeline and a drying component. The humidity sensor and the second control valve are arranged sequentially on the circulation pipeline. The drying pipeline is located downstream of the humidity sensor, and the drying pipeline is connected in parallel with the second control valve. The drying component is arranged on the drying pipeline, and the drying component is used to dry the gas.

[0009] Furthermore, the drying component includes a third control valve and a dryer, and the third control valve and the dryer are sequentially arranged on the drying pipeline.

[0010] Furthermore, the flow detection component includes a fourth control valve, a stagnation container, a nozzle group, a vacuum container and a vacuum pump which are sequentially arranged on the circulation pipeline. The nozzle group is arranged in the stagnation container, and the nozzle group is respectively connected to the stagnation container and the vacuum container. The vacuum pump is used to adjust the pressure in the vacuum container.

[0011] Furthermore, the flow detection component includes multiple nozzle groups arranged in parallel, each nozzle group includes a sonic nozzle, a branch pipe and a switch valve, one end of the branch pipe extends into the stagnation container and is connected to the sonic nozzle, the other end of the branch pipe is connected to the vacuum container, the switch valve is arranged on the branch pipe, and the switch valve is located between the stagnation container and the vacuum container.

[0012] Furthermore, the flow detection component also includes a first pressure sensor and a first temperature sensor, which are sequentially arranged on the flow pipeline, and the first temperature sensor is located upstream of the fourth control valve.

[0013] Furthermore, the flow detection assembly further includes a second pressure sensor, a second temperature sensor and a third pressure sensor. The second pressure sensor and the second temperature sensor are arranged on the stagnation container, and the third pressure sensor is arranged on the vacuum container.

[0014] Furthermore, the gas flow meter calibration device also includes a connecting joint and a fifth control valve, which are arranged sequentially on the circulation pipeline. The connecting joint is arranged at the air inlet, the connecting joint is connected to the gas source, and the fifth control valve is located between the connecting joint and the humidity monitoring component.

[0015] By applying the technical solution of the present invention, a flow detection component is set on the circulation pipeline, and the flow meter to be calibrated is set downstream of the flow detection component to ensure that the various parameters and flow of the gas passing through the flow meter to be calibrated are the same as when passing through the flow detection component, thereby ensuring the calibration accuracy. A monitoring component is also provided on the circulation pipeline, and the monitoring component includes a humidity monitoring component and a concentration monitoring component, and the humidity monitoring component is located upstream of the concentration monitoring component and the flow detection component. Through the above-mentioned setting, the humidity monitoring component and the concentration monitoring component will monitor the humidity and concentration of the gas entering the circulation pipeline. When the humidity and concentration of the gas reach the preset value, the flow of the gas is detected and calculated by the flow detection component to calibrate the flow meter to be calibrated, which greatly reduces the influence of the humidity and concentration of the gas on the detection results and calibration accuracy, and further improves the accuracy of the calibration results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of this application are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 The figure shows a schematic structural diagram of a gas flow meter calibration device provided by the present invention.

[0018] The above drawings include the following reference numerals:

[0019] 01. Flow meter to be calibrated;

[0020] 10. Circulation pipeline; 11. Air inlet; 12. Air outlet;

[0021] 13. Connecting joint; 14. Fifth control valve;

[0022] 20. Flow detection component;

[0023] 21. Fourth control valve; 22. Stagnation vessel;

[0024] 23. Nozzle group; 231. Sonic nozzle; 232. Branch pipe; 233. Switch valve;

[0025] 241. Vacuum container; 242. Vacuum pump;

[0026] 25. First pressure sensor; 26. First temperature sensor;

[0027] 27. Second pressure sensor; 28. Second temperature sensor;

[0028] 29. Third pressure sensor;

[0029] 30. Humidity monitoring component;

[0030] 31. Humidity sensor; 32. Second control valve; 33. Drying pipeline;

[0031] 34. Drying assembly; 341. Third control valve; 342. Dryer;

[0032] 40. Concentration monitoring component;

[0033] 41. Concentration monitoring pipeline; 410. Exhaust port;

[0034] 42. Concentration sensor;

[0035] 43. First control valve. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] like Figure 1 As shown, an embodiment of the present invention provides a gas flow meter calibration device, which includes: a circulation pipeline 10, a flow detection component 20 and a monitoring component. The circulation pipeline 10 has an air inlet 11 and an air outlet 12 that are relatively arranged, and the air inlet 11 is connected to the gas source. The flow meter to be calibrated is arranged on the circulation pipeline. The flow detection component 20 is arranged on the circulation pipeline 10, and the flow detection component 20 is used to detect the flow of the gas source in the circulation pipeline 10. The flow meter to be calibrated 01 is arranged on the circulation pipeline 10 and is located downstream of the flow detection component 20. The monitoring component is arranged on the circulation pipeline 10, and the monitoring component includes a humidity monitoring component 30 and a concentration monitoring component 40 that are arranged in sequence. The humidity monitoring component 30 is located upstream of the concentration monitoring component 40 and the flow detection component 20.

[0038] Applying the technical solution of the present invention, a flow detection component 20 is provided on the circulation pipeline 10, and the flow meter to be calibrated 01 is provided downstream of the flow detection component 20 to ensure that the various parameters and flow rate of the gas passing through the flow meter to be calibrated 01 are the same as when passing through the flow detection component 20, thereby ensuring the calibration accuracy. A monitoring component is also provided on the circulation pipeline 10, and the monitoring component includes a humidity monitoring component 30 and a concentration monitoring component 40. The humidity monitoring component 30 is located upstream of the concentration monitoring component 40 and the flow detection component 20. Through the above-mentioned arrangement, the humidity monitoring component 30 and the concentration monitoring component 40 will monitor the humidity and concentration of the gas entering the circulation pipeline 10. When the humidity and concentration of the gas reach the preset value, the flow rate of the gas is detected and calculated by the flow detection component 20 to calibrate the flow meter to be calibrated 01, which greatly reduces the influence of the humidity and concentration of the gas on the detection results and calibration accuracy, and further improves the accuracy of the calibration results. Among them, the gas source is hydrogen. In other embodiments, different types of gases can be replaced according to different application scenarios.

[0039] In this embodiment, the connection relationship between the concentration monitoring component 40 and the flow detection component 20 is not limited. The concentration monitoring component 40 and the flow detection component 20 can be arranged in series on the circulation pipeline 10, or in parallel. The choice can be made based on the actual application scenario and detection requirements.

[0040] Specifically, in this embodiment, the preset value of the humidity monitoring component 30 is 0%, and the preset value of the concentration monitoring component 40 is 100%. This setting can minimize the impact of the water content and impurities in the gas on the detection values ​​of the flow detection component 20 and the flow meter to be calibrated 01. In other embodiments of the present application, the preset value of the humidity monitoring component 30 and the preset value of the concentration monitoring component 40 can be selected according to actual working conditions.

[0041] The concentration monitoring assembly 40 includes a concentration monitoring line 41, a concentration sensor 42, and a first control valve 43. The concentration monitoring line 41 is connected to the circulation line 10, and the connection between the concentration monitoring line 41 and the circulation line 10 is located between the humidity monitoring assembly 30 and the flow detection assembly 20. The concentration sensor 42 is provided on the concentration monitoring line 41, and the concentration monitoring line 41 has an exhaust port 410. The exhaust port 410 is located downstream of the concentration sensor 42 and is used to discharge the fluid in the concentration monitoring line 41. The first control valve 43 is provided on the concentration monitoring line 41 and upstream of the concentration sensor 42. An on-off valve is provided at the exhaust port 410. Through the above-mentioned setting, the concentration of the gas in the circulation pipeline 10 will be monitored before entering the flow detection component 20. When there are impurities in the pipeline in the gas flow meter calibration device, the gas concentration detected by the concentration sensor 42 will be lower than the preset value. At this time, the on-off valve is opened to discharge the gas whose concentration has not reached the preset value from the exhaust port 410. In this way, the influence of impurities in the circulation pipeline 10 on the gas concentration can be minimized, thereby reducing the subsequent influence on the gas flow detection results. The gas whose concentration has not reached the preset value will not flow into the flow detection component 20 and the flow meter to be calibrated 01, and will not affect the detection results, thereby improving the calibration accuracy of the gas flow meter calibration device; when the concentration sensor 42 monitors that the gas concentration value has reached the preset value, it closes the first control valve 43, and the gas that subsequently reaches the preset concentration value is passed along the circulation pipeline 10 into the flow detection component 20.

[0042] In this embodiment, the specific position of the exhaust port 410 is not limited, and it can be connected to the flow pipeline 10 or directly connected to the outside.

[0043] Specifically, concentration sensor 42 is a gas concentration sensor. The present application does not limit the type of concentration sensor 42 , and may include a semiconductor gas sensor, a catalytic combustion gas sensor, or a thermal conductivity cell gas sensor. In this embodiment, concentration sensor 42 is a portable gas chromatograph, which not only reduces device cost but also reduces weight, facilitating shipment.

[0044] In the present application, the exhaust port 410 is connected to the gas outlet 12. By the above arrangement, the exhaust port 410 is connected to the gas outlet 12, which simplifies the structure and space occupation of the gas flow meter calibration device, making the device miniaturized and convenient for assembly and storage.

[0045] Among them, the humidity monitoring component 30 includes a humidity sensor 31, a second control valve 32, a drying pipeline 33 and a drying component 34. The humidity sensor 31 and the second control valve 32 are arranged in sequence on the circulation pipeline 10. The drying pipeline 33 is located downstream of the humidity sensor 31, and the drying pipeline 33 is connected in parallel with the second control valve 32. The drying component 34 is arranged on the drying pipeline 33. The drying component 34 is used to dry the gas. Through the above-mentioned setting, after the gas source enters the gas flow meter calibration device, it will first pass through the humidity sensor 31 for humidity monitoring to confirm whether the water content of the gas in the circulation pipeline reaches the preset value. If the preset value of the humidity is reached, the second control valve is opened and the gas is circulated to the concentration monitoring component 40 for concentration monitoring; if the preset value of the humidity is not reached, the second control valve is closed, and the gas enters the drying pipeline 33, and the moisture in the gas is dried by the drying component 34 before entering the concentration monitoring component 40 to reduce the influence of the water content on the gas flow detection. In this way, the dryness of the gas can be ensured, and there is no need to repeatedly introduce a large amount of gas for a long time, which saves the gas source and improves the calibration accuracy and efficiency.

[0046] Specifically, the drying component 34 can be configured as a device or technology such as a dryer, a condenser or an adsorbent.

[0047] In this application, drying assembly 34 includes a third control valve 341 and a dryer 342, which are sequentially arranged on drying pipeline 33. With this arrangement, when the humidity of the gas does not reach a preset value, third control valve 341 is opened, allowing the gas to enter dryer 342 for drying. This simplifies the pipeline structure design while enabling the selection of pipelines for different gas operating conditions, making the device more operable and enhancing its flexibility and practicality.

[0048] Specifically, the flow detection assembly 20 further includes a fourth control valve 21, a stagnation container 22, a nozzle assembly 23, a vacuum container 241, and a vacuum pump 242, which are sequentially arranged on the flow pipeline 10. The nozzle assembly 23 is in communication with the stagnation container 22 and the vacuum container 241, respectively. The vacuum pump 242 is used to regulate the pressure within the vacuum container 241. With this arrangement, after the gas passes through the humidity monitoring assembly 30 and the concentration monitoring assembly 40, and the concentration and humidity of the gas in the pipeline reach preset values, the fourth control valve 21 is opened, allowing the gas to enter the stagnation container 22. At this point, the vacuum pump 242 is activated to reduce the pressure in the vacuum container 241 to a negative pressure, ensuring that the allowable pressure downstream of the nozzle assembly 23 meets the critical backpressure ratio, thereby satisfying the detection conditions.

[0049] In this embodiment, the nozzle group 23 uses a Venturi nozzle, and the flow rate of the gas in the circulation pipeline 10 can be detected and calculated according to the method and formula in the standard GB / T21188-2007 "Measuring gas flow rate using a critical flow Venturi nozzle". This is existing technology and will not be repeated here.

[0050] In other embodiments, the flow detection component 20 may also detect the gas flow using a small gas flow detection system or a variable medium positive pressure gas flow standard device or other devices or methods.

[0051] The flow detection assembly 20 includes multiple nozzle groups 23 arranged in parallel. Each nozzle group 23 includes a sonic nozzle 231, a branch pipe 232, and an on / off valve 233. One end of the branch pipe 232 extends into the stagnation container 22 and communicates with the sonic nozzle 231. The other end of the branch pipe 232 communicates with the vacuum container 241. The on / off valve 233 is mounted on the branch pipe 232 and positioned between the stagnation container 22 and the vacuum container 241. This arrangement allows the number of nozzle groups 23 to be opened to be determined and selected based on the gas flow rate in the circulation pipeline, improving operational convenience.

[0052] Furthermore, the flow detection assembly 20 also includes a first pressure sensor 25 and a first temperature sensor 26. The first pressure sensor 25 and the first temperature sensor 26 are sequentially arranged on the circulation pipeline 10, and the first temperature sensor 26 is located upstream of the fourth control valve 21. With this arrangement, before starting to detect the gas flow, the stability of the gas is first confirmed to avoid excessive fluctuations in the gas pressure and temperature that may affect the detection results of the flow detection assembly 20.

[0053] The flow detection assembly 20 further includes a second pressure sensor 27, a second temperature sensor 28, and a third pressure sensor 29. The second pressure sensor 27 and the second temperature sensor 28 are disposed on the stagnation container 22, while the third pressure sensor 29 is disposed on the vacuum container 241. Through these devices, the second pressure sensor 27 and the second temperature sensor 28 can detect the pressure and temperature within the stagnation container 22, while the third pressure sensor 29 can detect the pressure within the vacuum container 241. This allows for real-time monitoring of the pressure and temperature at the front end of the sonic nozzle 231, as well as the pressure at the rear end of the sonic nozzle 231, thereby recording various gas parameters for calculation of the gas flow rate.

[0054] In the present application, the gas flow meter calibration device further includes a connector 13 and a fifth control valve 14, which are sequentially arranged on the circulation pipeline 10. The connector 13 is arranged at the air inlet 11 and is in communication with the gas source. The fifth control valve 14 is located between the connector 13 and the humidity monitoring assembly 30. Through the above arrangement, the connector 13 facilitates the connection of the gas flow meter calibration device with other equipment and facilitates online real-time calibration. The fifth control valve 14 is configured as a flow control valve, which facilitates the control of the flow of gas in the circulation pipeline 10 and the monitoring of humidity.

[0055] The technical solution provided by this application has the following advantages:

[0056] 1. A new humidity monitoring component can remove moisture from the gas to be tested, thereby improving the accuracy and efficiency of calibration work;

[0057] 2. Added concentration monitoring component to achieve quantitative analysis of the concentration of the gas to be tested, thereby improving the accuracy of the calibration results;

[0058] 3. By adding a monitoring component upstream of the flow detection component, online monitoring can be achieved, thereby improving the convenience of calibration work.

[0059] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0060] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0061] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0062] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0063] In addition, it should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A gas flow meter calibration device, characterized in that: The gas flow meter calibration device comprises: A circulation pipeline (10) having an air inlet (11) and an air outlet (12) arranged opposite to each other, wherein the air inlet (11) is connected to an air source; A flow detection component (20) is arranged on the circulation pipeline (10), the flow detection component (20) is used to detect the flow of gas in the circulation pipeline (10), and the flow meter (01) to be calibrated is arranged on the circulation pipeline (10) and is located downstream of the flow detection component (20); A monitoring component is arranged on the circulation pipeline (10), and the monitoring component comprises a humidity monitoring component (30) and a concentration monitoring component (40). The humidity monitoring component (30) is located upstream of the concentration monitoring component (40) and the flow detection component (20).

2. The gas flow meter calibration device according to claim 1, characterized in that: The concentration monitoring component (40) comprises: A concentration monitoring pipeline (41) is connected to the circulation pipeline (10), and the connection between the concentration monitoring pipeline (41) and the circulation pipeline (10) is located between the humidity monitoring component (30) and the flow detection component (20); a concentration sensor (42) disposed on the concentration monitoring pipeline (41); the concentration monitoring pipeline (41) having an exhaust port (410); the exhaust port (410) being located downstream of the concentration sensor (42); the exhaust port (410) being used to discharge the fluid in the concentration monitoring pipeline (41); The first control valve (43) is arranged on the concentration monitoring pipeline (41) and is located upstream of the concentration sensor (42).

3. The gas flow meter calibration device according to claim 2, characterized in that: The exhaust port (410) is in communication with the air outlet (12).

4. The gas flow meter calibration device according to claim 1, characterized in that: The humidity monitoring component (30) comprises a humidity sensor (31), a second control valve (32), a drying pipeline (33) and a drying component (34); the humidity sensor (31) and the second control valve (32) are arranged in sequence on the circulation pipeline (10); the drying pipeline (33) is located downstream of the humidity sensor (31), and the drying pipeline (33) is connected in parallel with the second control valve (32); the drying component (34) is arranged on the drying pipeline (33), and the drying component (34) is used to dry the gas.

5. The gas flow meter calibration device according to claim 4, characterized in that: The drying component (34) comprises a third control valve (341) and a dryer (342), and the third control valve (341) and the dryer (342) are sequentially arranged on the drying pipeline (33).

6. The gas flow meter calibration device according to claim 1, characterized in that: The flow detection assembly (20) further comprises a fourth control valve (21), a stagnation container (22), a nozzle group (23), a vacuum container (241) and a vacuum pump (242) which are sequentially arranged on the circulation pipeline (10); the nozzle group (23) is respectively connected to the stagnation container (22) and the vacuum container (241); and the vacuum pump (242) is used to adjust the pressure in the vacuum container (241).

7. The gas flow meter calibration device according to claim 6, characterized in that: The flow detection assembly (20) comprises a plurality of nozzle groups (23) arranged in parallel, each nozzle group (23) comprising a sonic nozzle (231), a branch pipe (232) and a switch valve (233), one end of the branch pipe (232) extends into the stagnation container (22) and communicates with the sonic nozzle (231), the other end of the branch pipe (232) is communicated with the vacuum container (241), the switch valve (233) is arranged on the branch pipe (232), and the switch valve (233) is located between the stagnation container (22) and the vacuum container (241).

8. The gas flow meter calibration device according to claim 6, characterized in that: The flow detection component (20) further comprises a first pressure sensor (25) and a first temperature sensor (26), wherein the first pressure sensor (25) and the first temperature sensor (26) are arranged in sequence on the circulation pipeline (10), and the first temperature sensor (26) is located upstream of the fourth control valve (21).

9. The gas flow meter calibration device according to claim 6, characterized in that: The flow detection assembly (20) further comprises a second pressure sensor (27), a second temperature sensor (28) and a third pressure sensor (29); the second pressure sensor (27) and the second temperature sensor (28) are arranged on the stagnation container (22), and the third pressure sensor (29) is arranged on the vacuum container (241).

10. The gas flow meter calibration device according to claim 2, characterized in that: The gas flow meter calibration device also includes a connecting joint (13) and a fifth control valve (14), wherein the connecting joint (13) and the fifth control valve (14) are arranged in sequence on the circulation pipeline (10), the connecting joint (13) is arranged at the air inlet (11), the connecting joint (13) is connected to the air source, and the fifth control valve (14) is located between the connecting joint (13) and the humidity monitoring component (30).

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