Calibration device of standard container applied to gas flow standard device

Abstract

The utility model relates to a calibration device of a standard container applied to a gas flow standard device. The calibration device comprises the standard container; the vacuum pump is connected with the standard container through a first stop valve and is used for extracting gas in the standard container; nitrogen is stored in the nitrogen tank, and the nitrogen tank is used for inputting nitrogen into the standard container to replace air in the standard container; one end of the disconnecting structure is connected with the standard container through a second stop valve, the other end of the disconnecting structure is connected with the nitrogen tank through a third stop valve, and the disconnecting structure has a communication state enabling the standard container to be communicated with the nitrogen tank and a disconnection state enabling the standard container to be disconnected from the nitrogen tank; and the balance structure is configured to weigh the nitrogen tank when the disconnecting structure is in the disconnected state, so that the accurate determination of the volume value of the standard container can be realized, the nitrogen tank and the standard container can be quickly connected or disconnected through the disconnecting structure, the operation is convenient and quick, and the detection time is shortened.

Description

Technical Field

[0001] This utility model relates to the field of flow metering technology, specifically to a calibration device for a standard container used in a gas flow standard device. Background Technology

[0002] A gas flow standard device is a gas flow measurement instrument characterized by high precision, good stability, high degree of automation, and wide applicability. It has extensive applications in industrial production, environmental monitoring, and scientific research. The gas flow standard device calculates the mass flow rate of the gas by measuring the changes in the thermodynamic temperature (T), absolute pressure (P), and time (t) of the gas entering or exiting a standard container of fixed volume within a certain time interval. When gas flows into or out of the standard container at a certain flow rate, the mass of the gas inside the container will change. This change can be indirectly obtained by measuring T, P, and t. The standard volume value of the standard container needs to be obtained in advance through a calibration device. The accuracy of the standard volume value of the standard container is very important; however, existing calibration devices for standard containers suffer from complex calibration methods and low accuracy.

[0003] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects. Utility Model Content

[0004] In view of this, this application provides a calibration device for a standard container used in a gas flow standard device to solve at least one problem existing in the prior art, comprising:

[0005] Standard containers;

[0006] A vacuum pump, connected to the standard container via a first shut-off valve, is used to extract gas from the standard container;

[0007] A nitrogen cylinder containing nitrogen is used to introduce nitrogen into the standard container to replace the air inside the standard container.

[0008] The detachment structure has one end connected to the standard container via a second shut-off valve and the other end connected to the nitrogen tank via a third shut-off valve. The detachment structure has both a connected state (allowing the standard container to communicate with the nitrogen tank) and a disconnected state (allowing the standard container to disconnect from the nitrogen tank).

[0009] The balance structure is configured to weigh the nitrogen tank when the disconnection structure is in the disconnected state.

[0010] Optionally, the calibration device for the standard container used in the gas flow standard device described above further includes a pressure detection element and a temperature detection element disposed on the standard container.

[0011] Optionally, the calibration device for the standard container used in the gas flow standard device described above further includes a windproof cover installed on the outside of the nitrogen tank.

[0012] Optionally, the calibration device for the standard container applied in the gas flow standard device described above further includes a first pipeline for connecting the standard container to the disconnection structure and for connecting the nitrogen tank to the disconnection structure;

[0013] The disconnection structure includes a second pipeline for connecting to the first pipeline. When the disconnection structure is in a connected state, the first pipeline and the second pipeline partially overlap.

[0014] Optionally, in the above-mentioned calibration device for a standard container used in a gas flow standard device, the disconnection structure is provided with a quick-release component, which is used to switch the disconnection structure between the disconnected state and the connected state.

[0015] Optionally, in the above-mentioned calibration device for a standard container used in a gas flow standard device, the detachment structure is provided with a magnetic suction element, and the first pipeline is provided with an adsorption element adapted to the magnetic suction element. When the detachment structure is in a connected state, the magnetic suction element and the adsorption element are attracted together.

[0016] Compared with the prior art, this application has the following beneficial effects: by setting up a standard container, a vacuum pump connected to the standard container, a nitrogen tank, a disconnection structure, and a balance structure, one end of the disconnection structure is connected to the standard container and the other end is connected to the nitrogen tank. The disconnection structure has a connected state that connects the standard container and the nitrogen tank and a disconnected state that disconnects the standard container and the nitrogen tank. When the disconnection structure is in the connected state, the nitrogen tank can be stably connected to the standard container, and nitrogen can be quickly introduced into the standard container. When the disconnection structure is in the disconnected state, the standard container is disconnected from the nitrogen tank, so that the balance structure can measure the mass of the nitrogen tank. This enables the accurate determination of the volume of the standard container. It also allows for quick connection or disconnection of the nitrogen tank and the standard container through the disconnection structure, which is convenient, fast, and reduces the detection time. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the calibration device for a standard container used in a gas flow standard device according to this embodiment.

[0018] Figure descriptions: 1-vacuum pump, 2-first shut-off valve, 3-standard container, 31-pressure sensor, 32-temperature sensor, 4-second shut-off valve, 5-disconnection structure, 6-third shut-off valve, 7-nitrogen tank, 8-wind shield, 9-balance structure. Detailed Implementation

[0019] The exemplary embodiments disclosed in this application will now be described in more detail. Numerous specific details are set forth in the following description to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without one or more of these details. In other instances, to avoid confusion with this application, some technical features well-known in the art have not been described; that is, not all features of actual embodiments are described herein, nor are well-known functions and structures described in detail.

[0020] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0021] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used here for convenience to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of devices in use and operation.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “ / the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0023] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solution of this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0024] Please refer to Figure 1 As shown in the preferred embodiment of this application, a calibration device for a standard container 3 used in a gas flow standard device includes a standard container 3, a vacuum pump 1 and a nitrogen tank 7 connected to the standard container 3 via a first shut-off valve 2, a disconnection structure 5, and a balance structure 9. The vacuum pump 1 is used to extract gas from the standard container 3. The nitrogen tank 7 stores nitrogen gas, which is used to introduce nitrogen gas into the standard container 3 to replace the air inside, facilitating subsequent calibration operations. One end of the disconnection structure 5 is connected to the standard container 3 via a second shut-off valve 4, and the other end is connected to the nitrogen tank 7 via a third shut-off valve 6. The disconnection structure 5 has a connected state that connects the standard container 3 and the nitrogen tank 7, and a disconnected state that disconnects the standard container 3 from the nitrogen tank 7. The balance structure 9 is configured to weigh the nitrogen tank 7 when the disconnection structure 5 is in the disconnected state.

[0025] Understandably, the disconnection structure 5 can switch between a connected state and a disconnected state, so that the connection state between the standard container 3 and the nitrogen tank 7 can be flexibly switched. When the disconnection structure 5 is in the connected state, the nitrogen in the nitrogen tank 7 can be stably delivered to the standard container 3. When the disconnection structure 5 is in the disconnected state, the nitrogen tank 7 can be weighed using the balance structure 9 to accurately measure the mass of nitrogen input to the standard container 3, thereby providing an accurate basis for calculating parameters such as gas flow rate and achieving accurate calibration of the standard container 3.

[0026] In this embodiment, the nitrogen gas is 99.9999% high-purity nitrogen.

[0027] In an optional embodiment, the calibration device further includes a pressure detection element 31 and a temperature detection element 32 disposed on the standard container 3. The pressure detection element 31 is used to detect the pressure inside the standard container 3, and the temperature detection element 32 is used to detect the temperature inside the standard container 3, so as to improve the calibration accuracy.

[0028] In an optional embodiment, the calibration device further includes a windproof cover 8 covering the outside of the nitrogen tank 7 to block the influence of external airflow on the nitrogen tank 7 and affect the weighing accuracy of the balance structure 9.

[0029] In an optional embodiment, the calibration device further includes a first conduit for connecting the standard container 3 to the disconnection structure 5 and for connecting the nitrogen tank 7 to the disconnection structure 5; the disconnection structure 5 includes a second conduit for connecting to the first conduit, and when the disconnection structure 5 is in a connected state, the first conduit and the second conduit partially overlap.

[0030] Understandably, when the disconnected structure 5 is in the connected state, the first pipeline and the second pipeline partially overlap, which can ensure a tight connection between the first pipeline and the second pipeline, ensure that the gas will not leak during transportation, and ensure the pressure in the nitrogen tank 7 and the standard container 3, thereby improving the overall stability and reliability of the calibration device.

[0031] In an optional embodiment, the detachment structure 5 is provided with a quick-release component, which is used to switch the detachment structure 5 between a disconnected state and a connected state. In this embodiment, the detachment structure 5 is provided with a magnetic suction component, and an adsorption component adapted to the magnetic suction component is provided on the first pipeline. When the detachment structure 5 is in the connected state, the magnetic suction component and the adsorption component are attracted together.

[0032] Understandably, by setting up magnetic and adsorption components, not only can the connection stability of the first and second pipelines be improved, but the connection and disconnection of the first and second pipelines can also be quickly realized, which greatly shortens the time required for state transition, improves the operational efficiency of the calibration process, and eliminates the need for complicated tools or cumbersome steps, reducing the operational difficulty and labor intensity of operators, making the calibration device easier for non-professionals to use and expanding its scope of application.

[0033] The calibration process of the calibration device in this embodiment is as follows:

[0034] (1) Turn on the vacuum pump, open the first shut-off valve and close the second shut-off valve to extract the air from the standard container. Then turn off the vacuum pump and the first shut-off valve, and open the second shut-off valve and the third shut-off valve so that the disconnected structure is in a connected state, so that the high-purity nitrogen in the nitrogen tank can be filled into the standard container.

[0035] (2) Repeat step (1) until the remaining air content in the standard container is no more than 0.002%.

[0036] (3) Close the third shut-off valve, disconnect the structure and start the balance structure and level it (measure the eccentricity and standard deviation before use, and keep the nitrogen tank in the same direction and position during use).

[0037] (4) Turn on the vacuum pump again, open the first shut-off valve, close the second shut-off valve, extract the nitrogen gas in the standard container, observe the indication values ​​of the pressure and temperature detectors until the pressure in the standard container reaches below 1 kPa, and then turn off the vacuum pump and the first shut-off valve.

[0038] (5) After the nitrogen state in the standard container stabilizes, observe the readings of the pressure and temperature sensors to obtain the absolute pressure P in the standard container before nitrogen filling. e and T e .

[0039] (6) Open the second and third shut-off valves to make the disconnection structure connected, fill the standard container with nitrogen from the nitrogen tank until the pressure in the standard container reaches 50 kPa, then stop filling, close the second and third shut-off valves to make the disconnection structure disconnected.

[0040] (7) Due to the consumption of nitrogen, the pressure inside the nitrogen tank drops, causing condensation and frost to form on the outer surface of the nitrogen tank. Wipe the outer surface of the nitrogen tank dry and let it dry for a period of time, waiting for the temperature of the nitrogen tank to rise back to the ambient temperature.

[0041] (8) Adjust the weights on the other side of the balance structure to make the balance structure rebalanced, and record the mass m1 after adjusting the weights when the nitrogen gas is first filled.

[0042] (9) Repeat steps (6)-(8) to repeatedly fill the standard container with nitrogen until the pressure inside the standard container reaches 300 kPa, and obtain m1, m2, m3...m in sequence. k .

[0043] (10) After the nitrogen state in the standard container stabilizes, observe the readings of the pressure and temperature sensors to obtain the absolute pressure P after the standard container is filled with nitrogen. f and temperature T f .

[0044] (11) Calculate the standard volume value V for this calibration according to the following formula. N :

[0045]

[0046] In the formula:

[0047] C b —Buoyancy correction factor;

[0048] p N —Standard pressure is 101325 Pa;

[0049] T N —Standard temperature is 293.15K;

[0050] z N —The compressibility coefficient of nitrogen is 0.99978;

[0051] ρ N —The density of nitrogen under standard conditions is 1.1648 kg / m³;

[0052] α—the coefficient of linear expansion of a standard container;

[0053] θ—the wall temperature of a standard container;

[0054] p f —Absolute pressure of nitrogen gas after filling a standard container with nitrogen;

[0055] T f —Nitrogen temperature after filling a standard container with nitrogen;

[0056] Z f —Nitrogen compressibility coefficient after nitrogen filling in a standard container;

[0057] P e —Absolute pressure of nitrogen gas in a standard container before nitrogen filling;

[0058] T e —Nitrogen temperature in a standard container before purging;

[0059] Z e —Nitrogen compressibility coefficient before filling a standard container with nitrogen;

[0060] m j —The mass of nitrogen gas introduced during a single nitrogen purging process;

[0061] k — The number of times nitrogen was purged during this calibration.

[0062] (12) Repeat the above steps to calibrate the standard container multiple times to obtain the volume values ​​of multiple standard containers, and take the average value of the volume values ​​of several standard containers as the final standard container volume value.

[0063] The above is only one specific implementation of this application, and any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. A calibration device for a standard container used in a gas flow standard device, characterized in that, include: Standard containers; A vacuum pump, connected to the standard container via a first shut-off valve, is used to extract gas from the standard container; A nitrogen cylinder containing nitrogen is used to introduce nitrogen into the standard container to replace the air inside the standard container. The detachment structure has one end connected to the standard container via a second shut-off valve and the other end connected to the nitrogen tank via a third shut-off valve. The detachment structure has both a connected state (allowing the standard container to communicate with the nitrogen tank) and a disconnected state (allowing the standard container to disconnect from the nitrogen tank). The balance structure is configured to weigh the nitrogen tank when the disconnection structure is in the disconnected state.

2. The calibration device for a standard container applied in a gas flow standard device according to claim 1, characterized in that, The calibration device also includes pressure and temperature sensors mounted on the standard container.

3. The calibration device for a standard container applied in a gas flow standard device according to claim 1, characterized in that, The calibration device also includes a windproof cover installed on the outside of the nitrogen tank.

4. The calibration device for a standard container applied in a gas flow standard device according to claim 1, characterized in that, The calibration device further includes a first pipeline for connecting the standard container to the detachment structure and for connecting the nitrogen tank to the detachment structure; The disconnection structure includes a second pipeline for connecting to the first pipeline. When the disconnection structure is in a connected state, the first pipeline and the second pipeline partially overlap.

5. The calibration device for a standard container applied in a gas flow standard device according to claim 4, characterized in that, The detachment structure is provided with a quick-release component, which is used to switch the detachment structure between the disconnected state and the connected state.

6. The calibration device for a standard container applied in a gas flow standard device according to claim 5, characterized in that, The detachment structure is provided with a magnetic suction element, and the first pipeline is provided with an adsorption element adapted to the magnetic suction element. When the detachment structure is in a connected state, the magnetic suction element and the adsorption element are attracted together.

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