Dry label test device for gas flow meter

Abstract

The utility model relates to the technical field of gas flow meter calibration, and discloses a gas flow meter dry label test device, which comprises a gas injection pipeline and a detection pipeline, the gas injection pipeline comprises a plurality of gas injection branches connected in parallel, each gas injection branch is used for being communicated with an inner cavity of a gas flow meter and used for injecting different gas media into the inner cavity, and the detection pipeline is used for detecting the gas flow meter. The detection pipeline is provided with a temperature detection part and a pressure detection part which are communicated with the inner cavity, the temperature detection part is used for detecting the temperature in the detection pipeline, and the pressure detection part is used for measuring the pressure in the detection pipeline. According to the utility model, the plurality of gas injection branches connected in parallel are arranged, each gas injection branch is communicated with the inner cavity of the gas flow meter, and the plurality of gas injection branches can inject different gas media into the inner cavity respectively, so that different gas media can be selected according to the actual use environment of the gas flow meter during dry labeling; actually used natural gas components can be simulated for testing, and the detection precision of the gas flowmeter is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of gas flowmeter calibration, in particular to a dry calibration test device for a gas flowmeter. Background Art

[0002] The information provided in this part is only background information related to the present disclosure, and it is not necessarily prior art.

[0003] Gas ultrasonic flowmeters need to be periodically calibrated. Before calibration or after maintenance, dry calibration is required. By detecting the measured data of the temperature and pressure inside the flowmeter to be calibrated and the dry calibration device, and based on these data, the parameters set for the flowmeter are corrected to complete the calibration, so that the flowmeter to be calibrated works in the best state.

[0004] At present, the medium of the dry calibration device for gas ultrasonic flowmeters is nitrogen during dry calibration, which is inconsistent with the actual use environment of the ultrasonic flowmeter and cannot simulate the components of the actual natural gas for testing, affecting the detection accuracy of the ultrasonic flowmeter. Summary of the Utility Model

[0005] The purpose of the utility model is to at least solve the problem that the gas medium during dry calibration is inconsistent with the actual use environment of the ultrasonic flowmeter, and it cannot simulate the components of the actual natural gas for testing, affecting the detection accuracy. This purpose is achieved through the following technical solutions:

[0006] The utility model provides a dry calibration test device for a gas flowmeter, including:

[0007] An injection gas pipeline, including a plurality of parallel injection gas branches, each of the injection gas branches is used to communicate with the inner cavity of the gas flowmeter for respectively injecting different gas media into the inner cavity;

[0008] A detection pipeline, used to communicate with the inner cavity, a temperature detection component and a pressure detection component are arranged on the detection pipeline, the temperature detection component is used to detect the temperature in the detection pipeline, and the pressure detection component is used to measure the pressure in the detection pipeline.

[0009] By arranging a plurality of parallel injection gas branches in the dry calibration test device of the utility model, and each injection gas branch is respectively communicated with the inner cavity of the gas flowmeter, the plurality of injection gas branches can respectively inject different gas media into the inner cavity. During dry calibration, different gas media can be selected according to the actual use environment of the gas flowmeter, and the components of the actual natural gas can be simulated for testing, improving the detection accuracy of the gas flowmeter.

[0010] In addition, according to the dry calibration test device for a gas flowmeter of the utility model, the following additional technical features may also be provided:

[0011] In some embodiments of the present utility model, the gas injection shunt includes a gas cylinder and a connecting pipe. A pressure regulator is provided on the connecting pipe. The pressure regulator is arranged close to the gas cylinder and is used to regulate the pressure of the gas injected into the inner cavity.

[0012] In some embodiments of the present utility model, the gas injection pipeline further includes a main gas injection pipeline and a first connection assembly. The first connection assembly includes a first plug-in part and a first connecting part. The first connecting part is detachably connected to the first plug-in part. The main gas injection pipeline is connected to one of the first connecting part and the first plug-in part, and the gas injection shunt is connected to the other of the first connecting part and the first plug-in part.

[0013] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing part and a second pressing part. The first pressing part and the second pressing part are used for respectively sealingly connecting to both ends of the gas flowmeter. The main gas injection pipeline communicates with the inner cavity of the first pressing part, and the detection pipeline communicates with the inner cavity of the second pressing part.

[0014] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a vacuum extraction pipeline. The vacuum extraction pipeline includes a first extraction pipe, a second extraction pipe, and a second connection assembly. The second connection assembly includes a second plug-in part and a second connecting part that are detachably connected. One end of the first extraction pipe communicates with the inner cavity of the second pressing part, and the other end is connected to one of the second plug-in part and the second connecting part. One end of the second extraction pipe is connected to the other of the second plug-in part and the second connecting part, and the other end is connected to a vacuum extraction device.

[0015] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing part and a second pressing part. The first pressing part and the second pressing part are used for respectively sealingly connecting to both ends of the gas flowmeter. The gas injection pipeline communicates with the inner cavity of the first pressing part. The dry calibration test device for the gas flowmeter further includes a vacuum extraction pipeline. The vacuum extraction pipeline includes a first extraction pipe, a second extraction pipe, and a second connection assembly. The second connection assembly includes a second plug-in part and a second connecting part that are detachably connected. One end of the first extraction pipe communicates with the inner cavity of the second pressing part, and the other end is connected to one of the second plug-in part and the second connecting part. One end of the second extraction pipe is connected to the other of the second plug-in part and the second connecting part, and the other end is connected to a vacuum extraction device.

[0016] In some embodiments of the present utility model, the gas injection pipeline further includes a first connection assembly. The connection pipe includes a first connection pipe and a second connection pipe. The inlet end of the first connection pipe is communicated with the outlet end of the gas cylinder. The outlet end of the first connection pipe is communicated with the inlet end of the second connection pipe. The outlet end of the second connection pipe is communicated with the first connection assembly. The second connection pipe is a connecting hose.

[0017] In some embodiments of the present utility model, a first switch valve and a one-way valve are further provided on the main gas injection pipeline. The one-way valve is arranged on a side of the first switch valve away from the first connection assembly.

[0018] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing member and a second pressing member. The first pressing member and the second pressing member are used for respectively sealingly connecting with two ends of the gas flowmeter. The gas injection pipeline is communicated with the inner cavity of the first pressing member. The detection pipeline is communicated with the inner cavity of the second pressing member. A second switch valve and a safety valve are further arranged on the detection pipeline. The pressure detection member and the temperature detection member are located between the second switch valve and the safety valve. The second switch valve is closer to the second pressing member than the safety valve.

[0019] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing member and a second pressing member. The first pressing member and the second pressing member are used for respectively sealingly connecting with two ends of the gas flowmeter. The gas injection pipeline is communicated with the inner cavity of the first pressing member. The dry calibration test device for the gas flowmeter further includes an exhaust pipeline and a vacuum extraction pipeline. The detection pipeline, the exhaust pipeline and the vacuum extraction pipeline are respectively communicated with the second pressing member. A third switch valve is arranged on the exhaust pipeline. Description of the Drawings

[0020] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered as a limitation to the present utility model. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0021] Figure 1 Schematically shown is a structural schematic diagram of a dry calibration test device for a gas flowmeter according to an embodiment of the present utility model.

[0022] The reference numerals are as follows:

[0023] 10. Flowmeter main body; 11. First pressing member; 110. First flange; 12. Second pressing member; 120. Second flange;

[0024] 2. Gas injection pipeline; 20. Main gas injection pipeline; 21. First connection assembly; 22. Gas cylinder; 23. First connecting pipe; 24. Second connecting pipe; 25. First on-off valve; 26. Check valve; 27. Pressure regulating valve;

[0025] 30. Detection pipeline; 31. Pressure gauge; 32. Thermometer; 33. Second on-off valve; 34. Safety valve;

[0026] 4. Vacuum extraction pipeline; 40. First extraction pipe; 41. Second extraction pipe; 42. Second connection assembly; 43. Fourth on-off valve; 44. Vacuum pump;

[0027] 50. Exhaust pipeline; 51. Third on-off valve. Detailed implementation mode

[0028] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0029] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" as used herein may also include the plural forms. The terms "include", "comprise", "contain" and "have" are inclusive and thus specify the presence of the stated features, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0030] Although terms such as first, second, and third may be used herein to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Unless the context clearly indicates otherwise, terms such as "first", "second", and other numerical terms do not imply an order or sequence when used in the text. Therefore, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0031] For ease of description, spatial relative relationship terms may be used herein to describe the relationship of one element or feature shown in the figure to another element or feature, such as "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", etc. Such spatial relative relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is flipped, the element described as "below" or "beneath" another element or feature will then be oriented "above" or "over" the other element or feature. Thus, the exemplary term "below" can include both the upper and lower orientations.

[0032] As Figure 1 shown, according to an embodiment of the present invention, a dry calibration test device for a gas flowmeter is proposed. The gas flowmeter has an inner cavity. In this embodiment, the gas flowmeter is a gas ultrasonic flowmeter. The dry calibration test device includes an injection pipeline 2 and a detection pipeline 30. The injection pipeline 2 includes a plurality of parallel injection branches, and each injection branch is used to communicate with the inner cavity of the ultrasonic flowmeter to inject different gas media into the inner cavity respectively. The detection pipeline 30 is used to communicate with the inner cavity, and a temperature detection element and a pressure detection element are arranged on the detection pipeline 30. The temperature detection element is used to detect the temperature in the detection pipeline 30, and the pressure detection element is used to measure the pressure in the detection pipeline 30.

[0033] The dry calibration test device for the gas flowmeter of the present invention is provided with a plurality of parallel injection branches, and each injection branch communicates with the inner cavity of the ultrasonic flowmeter respectively. The plurality of injection branches can inject different gas media into the inner cavity respectively. When performing dry calibration, different gas media can be selected according to the actual use environment of the ultrasonic flowmeter, and the components of the natural gas actually used can be simulated for testing, improving the detection accuracy of the ultrasonic flowmeter.

[0034] In some embodiments of the present utility model, the gas injection branch includes a gas cylinder 22 and a connecting pipe. The connecting pipe is provided with a pressure regulator, which is arranged close to the gas cylinder 22 and is used to adjust the pressure of the gas injected into the inner cavity. Specifically, each gas injection branch includes a gas cylinder 22 and a connecting pipe. Different gases, such as nitrogen, methane or other gases similar to natural gas, are stored in each gas cylinder 22 respectively. A pressure regulator is arranged on the connecting pipe. The pressure regulator is a pressure regulating valve 27, which is arranged close to the gas cylinder 22 and is used to adjust the pressure of the gas injected into the inner cavity. Different gas media can be selected according to the actual use environment of the ultrasonic flowmeter, and the composition and pressure of the actual natural gas used can be simulated for testing, improving the detection accuracy of the ultrasonic flowmeter.

[0035] In some embodiments of the present utility model, the gas injection pipeline 2 further includes a main gas injection pipeline 20 and a first connection assembly 21. The first connection assembly 21 includes a first plug-in part and a first connecting part. The first connecting part is detachably connected to the first plug-in part. The main gas injection pipeline 20 is connected to one of the first connecting part and the first plug-in part, and the gas injection branch is connected to the other of the first connecting part and the first plug-in part. Specifically, a plurality of gas injection branches are collectively connected to an installation pipe. The first connecting part is arranged at one end of the installation pipe far from the gas injection branch. In this embodiment, the inlet end of the main gas injection pipeline 20 is provided with a first plug-in part, the outlet end of the main gas injection pipeline 20 is communicated with the inner cavity of the ultrasonic flowmeter, the gas injection branch is connected to the first connecting part, and the main gas injection pipeline 20 is detachably connected to the installation pipe through the first plug-in part and the first connecting part. When injecting gas, the first connecting part is plugged into the first plug-in part, and the on-off of the corresponding gas injection branch is controlled by the pressure regulating valve 27, so as to inject the corresponding gas medium into the inner cavity of the ultrasonic flowmeter. The operation is simple, which is convenient to realize the on-off of the gas injection pipeline 2. While improving the use speed, it avoids the danger of gas mixing caused by forgetting to cut off the gas injection branch, ensuring safety.

[0036] In other embodiments, the main gas injection pipeline 20 can also be connected to the first connecting part, and the gas injection branch is connected to the first plug-in part.

[0037] In this embodiment, the first connecting part includes a first female joint, the first plug-in part includes a first male joint, the outlet end of the installation pipe is provided with a first female joint, the inlet end of the main gas injection pipeline 20 is provided with a first male joint, and the first female joint and the first male joint are detachably connected.

[0038] In other embodiments, the first female joint can also be arranged at the inlet end of the main gas injection pipeline 20, and the first male joint can also be arranged at the outlet end of the installation pipe.

[0039] In some embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing member 11 and a second pressing member 12. The first pressing member 11 and the second pressing member 12 are used for sealingly connecting to both ends of the gas flowmeter respectively. The injection main pipeline 20 communicates with the inner cavity of the first pressing member 11, and the detection pipeline 30 communicates with the inner cavity of the second pressing member 12. Specifically, the ultrasonic flowmeter includes a flowmeter main body 10. Both ends of the flowmeter main body 10 are respectively provided with a first connection port and a second connection port. The first connection port and the second connection port communicate with the inner cavity of the flowmeter. The first pressing member 11 includes a first flange 110, and the first flange 110 is arranged at the first connection port of the flowmeter main body 10. The second pressing member 12 includes a second flange 120, and the second flange 120 is arranged at the second connection port of the flowmeter main body 10. During installation, the first flange 110 fits with the flange surface of the first connection port, and the first flange 110 is connected and fixed to the first connection port through a pressing bolt. Similarly, the second flange 120 fits with the flange surface of the second connection port, and the second flange 120 is connected and fixed to the second connection port through a pressing bolt. A sealing ring can also be arranged between the two flange surfaces. The sealing rings have different specifications to meet the tests of flowmeters of different specifications. By arranging the sealing ring, the leakage of the gas medium in the inner cavity of the ultrasonic flowmeter can be reduced, and the overall sealing performance of the ultrasonic flowmeter can be improved.

[0040] In some other embodiments of the present utility model, the dry calibration test device for the gas flowmeter further includes a vacuum extraction pipeline 4. The vacuum extraction pipeline 4 includes a first extraction pipe 40, a second extraction pipe 41, and a second connection assembly 42. The second connection assembly 42 includes a second pluggable connector and a second connecting member. One end of the first extraction pipe 40 communicates with the inner cavity of the second pressing member 12, and the other end is connected to one of the second pluggable connector and the second connecting member. One end of the second extraction pipe 41 is connected to the other of the second pluggable connector and the second connecting member, and the other end is connected to a vacuum extraction device. In this embodiment, the inlet end of the first extraction pipe 40 communicates with the inner cavity of the ultrasonic flowmeter. The outlet end of the first extraction pipe 40 is provided with a second pluggable connector. The inlet end of the second extraction pipe 41 is provided with a second connecting member. The outlet end of the second extraction pipe 41 is connected to a vacuum extraction device, and the vacuum extraction device is a vacuum pump 44, which is used to evacuate the inner cavity of the ultrasonic flowmeter.

[0041] In other embodiments, the outlet end of the first extraction pipe 40 can also be connected to the second connecting member, and the inlet end of the second extraction pipe 41 can also be connected to the second pluggable connector.

[0042] In this embodiment, the second connecting member includes a second male connector, the second plug-in member includes a second female connector. The inlet end of the first extraction pipe 40 communicates with the inner cavity of the ultrasonic flowmeter. The outlet end of the first extraction pipe 40 is provided with a second male connector. The inlet end of the second extraction pipe 41 is provided with a second female connector. The outlet end of the second extraction pipe 41 is connected to a vacuum extraction device, and the vacuum extraction device is a vacuum pump 44, which is used to evacuate the inner cavity of the ultrasonic flowmeter. A fourth switching valve 43 is also provided on the first extraction pipe 40. The fourth switching valve 43 is a needle valve, and the on-off of the vacuum extraction pipeline 4 is realized by setting the fourth switching valve 43.

[0043] In some embodiments of the present utility model, the connecting pipe includes a first connecting pipe 23 and a second connecting pipe 24. The inlet end of the first connecting pipe 23 communicates with the outlet end of the gas cylinder 22. The outlet end of the first connecting pipe 23 communicates with the inlet end of the second connecting pipe 24. The outlet end of the second connecting pipe 24 communicates with the first connecting assembly 21. The second connecting pipe 24 is a connecting hose. Specifically, this embodiment includes four gas injection branch paths, and one of the gas injection branch paths will be described in this embodiment. Both ends of the first connecting pipe 23 communicate with the gas cylinder 22 and the second connecting pipe 24 respectively. The second connecting pipe 24 communicates with the installation pipe. The outlet end of the installation pipe is connected to the first connecting member. The second connecting pipe 24 is a connecting hose, and the length of the connecting hose can be set according to the actual situation, which is convenient for the insertion and extraction of the first connecting member and the first plug-in member, and improves the insertion and extraction efficiency.

[0044] In some embodiments of the present utility model, a first switching valve 25 and a one-way valve 26 are also provided on the gas injection main pipeline 20. The one-way valve 26 is arranged on the side of the first switching valve 25 away from the first connecting assembly 21. Specifically, the first switching valve 25 is arranged close to the first plug-in member, and the one-way valve 26 is arranged on the side of the first switching valve 25 away from the first plug-in member. The first switching valve 25 is a needle valve, and the on-off of the gas injection main pipeline 20 is realized by setting the first switching valve 25; by setting the one-way valve 26, the one-way conduction from the gas injection branch path, the gas injection main pipeline 20 to the gas flowmeter is realized, so as to ensure the one-way flow of gas and improve safety. During operation, according to the actual requirements, determine the gas medium to be injected into the gas flowmeter, and then open the first switching valve 25 on the corresponding gas cylinder 22, and inject gas into the gas flowmeter through the connecting pipe.

[0045] It should be noted that the first switching valve 25, the second switching valve 33, the third switching valve 51 and the fourth switching valve 43 can also be set as ball valves or other structural members that can facilitate conduction or isolation.

[0046] In other embodiments, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing member 11 and a second pressing member 12. The first pressing member 11 and the second pressing member 12 are used for sealing connection with the two ends of the gas flowmeter respectively. The injection gas pipeline 2 communicates with the inner cavity of the first pressing member 11. The dry calibration test device for the gas flowmeter further includes a vacuum extraction pipeline 4. The vacuum extraction pipeline 4 includes a first extraction pipe 40, a second extraction pipe 41 and a second connection assembly 42. The second connection assembly 42 includes a second pluggable connector and a second connecting member. One end of the first extraction pipe 40 communicates with the inner cavity of the second pressing member 12, and the other end is connected to one of the second pluggable connector and the second connecting member. One end of the second extraction pipe 41 is connected to the other of the second pluggable connector and the second connecting member, and the other end is connected to a vacuum extraction device. It can be understood that in this embodiment, the injection gas pipeline 2 directly communicates with the inner cavity of the first pressing member 11. One end of the first extraction pipe 40 communicates with the inner cavity of the second pressing member 12. The other end of the first extraction pipe 40 is connected to a second male connector. One end of the second extraction pipe 41 is connected to a second female connector, and the other end of the second extraction pipe 41 is connected to a vacuum extraction device.

[0047] In other embodiments, the dry calibration test device for the gas flowmeter further includes a pressing device. The pressing device includes a first pressing member 11 and a second pressing member 12. The first pressing member 11 and the second pressing member 12 are used for sealing connection with the two ends of the gas flowmeter respectively. The injection gas pipeline 2 communicates with the inner cavity of the first pressing member 11, and the detection pipeline 30 communicates with the inner cavity of the second pressing member 12. The detection pipeline 30 is further provided with a second on-off valve 33 and a safety valve 34. A pressure detection member and a temperature detection member are located between the second on-off valve 33 and the safety valve 34. The second on-off valve 33 is closer to the second pressing member 12 than the safety valve 34. Specifically, the second on-off valve 33 is a needle valve. The on-off of the detection pipeline 30 is realized by setting the second on-off valve 33. The pressure detection member includes a pressure gauge 31, and the pressure gauge 31 measures the pressure in the detection pipeline 30. The temperature detection member is a thermometer 32, and the thermometer 32 measures the temperature in the detection pipeline 30. The threshold value of the safety valve 34 can be adjusted according to actual needs. The measured pressure of the pressure gauge 31 is compared with the preset threshold value of the safety valve 34. If the measured pressure is greater than the preset threshold value, the safety valve 34 makes the detection pipeline 30 conduct air release to ensure safety.

[0048] In other embodiments, the dry calibration test device for the gas flowmeter further includes a pressing device, which includes a first pressing member 11 and a second pressing member 12. The first pressing member 11 and the second pressing member 12 are used for sealing connection with the two ends of the gas flowmeter respectively. The injection pipeline 2 communicates with the inner cavity of the first pressing member 11. The dry calibration test device for the gas flowmeter further includes an exhaust pipeline 50 and a vacuum extraction pipeline 4. The detection pipeline 30, the exhaust pipeline 50 and the vacuum extraction pipeline 4 communicate with the second pressing member 12 respectively. The exhaust pipeline 50 is provided with a third switching valve 51. Specifically, the detection pipeline 30, the exhaust pipeline 50 and the vacuum extraction pipeline 4 communicate with the inner cavity of the second pressing member 12 respectively. The exhaust pipeline 50 is used to discharge the gas in the gas flowmeter; the third switching valve 51 is a needle valve, and the on-off of the exhaust pipeline 50 is realized by setting the third switching valve 51.

[0049] When the dry calibration test device for the gas flowmeter is working, first connect the injection pipeline 2, the vacuum extraction pipeline 4, the detection pipeline 30 and the exhaust pipeline 50 to the inner cavity of the ultrasonic flowmeter respectively, and then check that the first switching valve 25, the one-way valve 26, the pressure regulating valve 27, the second switching valve 33, the safety valve 34, the third switching valve 51 and the fourth switching valve 43 are all in the closed state. Then insert the second male connector and the second female connector to connect the first extraction pipe 40 and the second extraction pipe 41. Then, after opening the fourth switching valve 43, start the vacuum pump 44 to evacuate the inner cavity, and pump the original cavity air to the ultimate pressure of the vacuum, that is, negative pressure. Then turn off the vacuum pump 44, insert the first male connector and the first female connector, and open the first switching valve 25 and the one-way valve 26. Control the on-off of the injection branch communicating with the gas cylinder 22 storing nitrogen through the pressure regulating valve 27, inject nitrogen with a certain pressure into the inner cavity, and then open the third switching valve 51 to exhaust through the exhaust pipeline 50. The above operations of injecting nitrogen and exhausting gas are generally carried out three times to exhaust the air in the inner cavity. Then close the third switching valve 51, open the second switching valve 33, select the corresponding gas medium according to the composition of the natural gas actually used, ensure that the pressure and gas composition are the same as the actual working conditions, and conduct the dry calibration test of the flowmeter. The above dry calibration test measures the sound speed and then calculates the measurement error of the sound speed. For example, the sound speed measurement under normal pressure and different pressures of air, the sound speed measurement under normal pressure and different pressures of nitrogen, and the sound speed measurement under normal pressure and different pressures of methane or other similar natural gases. The dry calibration test device for the gas flowmeter of the present invention can simulate the composition and pressure of the natural gas actually used, improving the detection speed and use accuracy of the flowmeter.

[0050] As described above, it is only the preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims

1. A gas flow meter dry calibration test device, characterized in that: include: A gas injection pipeline, comprising a plurality of parallel gas injection branches, each of which is used to communicate with the inner cavity of the gas flow meter and is used to inject different gas media into the inner cavity respectively; The detection pipeline is used to communicate with the inner cavity. The detection pipeline is provided with a temperature detection component and a pressure detection component. The temperature detection component is used to detect the temperature in the detection pipeline, and the pressure detection component is used to measure the pressure in the detection pipeline.

2. The gas flow meter dry calibration test device according to claim 1, characterized in that: The gas injection branch includes a gas cylinder and a connecting pipe. The connecting pipe is provided with a pressure regulator. The pressure regulator is arranged close to the gas cylinder and is used to adjust the pressure of the gas injected into the inner cavity.

3. The gas flow meter dry calibration test device according to claim 1 or 2, characterized in that: The gas injection pipeline also includes a main gas injection line and a first connecting component, the first connecting component includes a first connector and a first connector, the first connector and the first connector are pluggable, the main gas injection line is connected to one of the first connector and the first connector, and the gas injection branch line is connected to the other of the first connector and the first connector.

4. The gas flow meter dry calibration test device according to claim 3, characterized in that: The gas flow meter dry standard test device also includes a clamping device, which includes a first clamping part and a second clamping part. The first clamping part and the second clamping part are used to be sealed and connected to the two ends of the gas flow meter respectively, the main gas injection line is connected to the inner cavity of the first clamping part, and the detection line is connected to the inner cavity of the second clamping part.

5. The gas flow meter dry calibration test device according to claim 4, characterized in that: The gas flow meter dry standard test device also includes a vacuum exhaust pipeline, which includes a first exhaust pipe, a second exhaust pipe and a second connecting assembly, the second connecting assembly includes a second plug-in connector and a second connecting member that can be plugged in and out, one end of the first exhaust pipe is connected to the inner cavity of the second clamping member, and the other end is connected to one of the second connector and the second connecting member, one end of the second exhaust pipe is connected to the other of the second connector and the second connecting member, and the other end is connected to the vacuum exhaust device.

6. The gas flow meter dry calibration test device according to claim 1, characterized in that: The gas flow meter dry standard test device also includes a clamping device, which includes a first clamping piece and a second clamping piece. The first clamping piece and the second clamping piece are used to be sealed and connected to the two ends of the gas flow meter respectively, and the gas injection pipeline is connected to the inner cavity of the first clamping piece. The gas flow meter dry standard test device also includes a vacuum exhaust pipeline, which includes a first exhaust pipe, a second exhaust pipe and a second connecting assembly. The second connecting assembly includes a pluggable second connector and a second connector. One end of the first exhaust pipe is connected to the inner cavity of the second clamping piece, and the other end is connected to one of the second connector and the second connector. One end of the second exhaust pipe is connected to the other of the second connector and the second connector, and the other end is connected to the vacuum exhaust device.

7. The gas flow meter dry calibration test device according to claim 2, characterized in that: The gas injection pipeline also includes a first connecting assembly, and the connecting pipe includes a first connecting pipe and a second connecting pipe. The inlet end of the first connecting pipe is connected to the outlet end of the gas cylinder, the outlet end of the first connecting pipe is connected to the inlet end of the second connecting pipe, and the outlet end of the second connecting pipe is connected to the first connecting assembly. The second connecting pipe is a connecting hose.

8. The gas flow meter dry calibration test device according to claim 3, characterized in that: The gas injection main line is further provided with a first switch valve and a one-way valve, and the one-way valve is provided on a side of the first switch valve away from the first connecting assembly.

9. The gas flow meter dry calibration test device according to claim 1, characterized in that: The gas flow meter dry standard test device also includes a clamping device, which includes a first clamping piece and a second clamping piece. The first clamping piece and the second clamping piece are used to be sealed and connected to the two ends of the gas flow meter respectively. The gas injection pipeline is connected to the inner cavity of the first clamping piece, and the detection pipeline is connected to the inner cavity of the second clamping piece. The detection pipeline is also provided with a second switch valve and a safety valve. The pressure detection piece and the temperature detection piece are located between the second switch valve and the safety valve, and the second switch valve is close to the second clamping piece relative to the safety valve.

10. The gas flow meter dry calibration test device according to claim 1, characterized in that: The gas flow meter dry standard test device also includes a clamping device, which includes a first clamping piece and a second clamping piece. The first clamping piece and the second clamping piece are used to be sealed and connected to the two ends of the gas flow meter respectively, and the gas injection pipeline is connected to the inner cavity of the first clamping piece. The gas flow meter dry standard test device also includes an exhaust pipeline and a vacuum exhaust pipeline. The detection pipeline, the exhaust pipeline and the vacuum exhaust pipeline are respectively connected to the second clamping piece, and the exhaust pipeline is provided with a third switch valve.

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