Pressure-resistant gas micro-flow calibrator

Abstract

The invention provides a pressure-resistant gas micro-flow calibrator which comprises a two-position four-way electromagnetic valve suitable for being communicated with gas to be measured, a volume pipe, a first position trigger switch, a second position trigger switch and a timer, the volume pipe comprises a fluid cavity, a piston, a first gas port and a second gas port, and the first gas port and the second gas port are formed in the two axial ends of the fluid cavity respectively; the fluid cavity comprises an initial position and an end position, the first position trigger switch and the second position trigger switch are located between the initial position and the end position, and gas to be detected is suitable for entering the fluid cavity through the first gas port and pushing the piston to move from the initial position to the end position. And when the piston passes through the first position trigger switch and the second position trigger switch, the timer is controlled to time to obtain a time parameter. The standard volume flow is obtained by reproducing a volume flow formula, and the method has the advantages of pressure resistance, small size of the calibrator, low requirement on the external environment, high accuracy, high portability and the like.

Description

Technical Field

[0001] This invention belongs to the field of flow measurement technology, and in particular relates to a pressure-resistant gas micro-flow calibrator. Background Technology

[0002] Pressure-resistant gas flow rate standard devices have wide applications in daily life and industrial production. From gas meters used in everyday life to the calibration of natural gas by Sinopec, gas flow rate standard devices are indispensable.

[0003] For the calibration of micro gas flow meters, the primary standard devices used both domestically and internationally mainly include the pVTt method, the volumetric method, and the Mt method. Most of these primary standard devices have environmental requirements and are typically installed in fixed locations such as laboratories, lacking portability. Therefore, when researching pressure-resistant micro gas flow standard devices, the size and portability of the standard device must be considered. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a pressure-resistant gas micro-flow calibrator to meet the needs of users.

[0005] To achieve the above objectives, the present invention provides a pressure-resistant gas micro-flow calibrator, comprising:

[0006] A two-position four-way solenoid valve, suitable for connecting the gas to be measured.

[0007] A volume tube includes a fluid chamber, a piston, a first air port, a second air port, and a third air port. The first and second air ports are respectively located at opposite axial ends of the fluid chamber. The fluid chamber includes an initial position and a final position. The gas to be measured is adapted to enter the fluid chamber through the third air port and hold the piston in the initial position.

[0008] A first position trigger switch and a second position trigger switch are both located between the initial position and the final position.

[0009] The timer is controlled by the first position trigger switch and the second position trigger switch.

[0010] The gas to be tested is adapted to enter the fluid cavity through the first gas port and push the piston from the initial position to the final position. During this process, when the piston passes the first position trigger switch, the timer starts timing, and when the piston passes the second position trigger switch, the timer stops timing.

[0011] Preferably, the system further includes a valve-1 pipeline and a valve-2 pipeline arranged in parallel. The valve-1 pipeline includes a first valve, which is adapted to control the connection between the two-position four-way solenoid valve and the first air port. The valve-2 pipeline includes a second valve, which is adapted to control the connection between the two-position four-way solenoid valve and the second air port.

[0012] Preferably, the system further includes a first pipeline and a second pipeline. The two-position four-way solenoid valve includes a first inlet, a first outlet, a first reversing port, and a second reversing port. The gas to be tested is adapted to enter the two-position four-way solenoid valve through the first inlet and to exit the two-position four-way solenoid valve through the first outlet. The first reversing port is connected to the valve one pipeline and the valve two pipeline through the first pipeline, respectively. The second reversing port is connected to the second air port through the second pipeline.

[0013] Preferably, the system also includes a pressure relief pipeline, which includes a pressure relief valve. The pressure relief pipeline is connected in parallel with the first valve pipeline and the second valve pipeline, and the pressure relief pipeline is connected to the first pipeline and the third air port, respectively.

[0014] As a preferred option, it also includes:

[0015] Check line, the check line including a check valve,

[0016] A third position trigger switch is disposed between the second position trigger switch and the termination position.

[0017] The volume tube includes a fourth gas port, and the check pipe is connected to the fourth gas port and the second pipe respectively. When the piston moves through the third position to trigger the switch, the check valve opens, and the gas to be tested in the volume tube can be discharged through the check pipe.

[0018] Preferably, the check valve is a butterfly valve structure, and the check valve includes a closing spring adapted to support the check valve in keeping it closed.

[0019] Preferably, the system further includes a fourth position trigger switch and a fifth position trigger switch suitable for monitoring the motion state of the piston, wherein the third position trigger switch and the fourth position trigger switch are disposed between the first position trigger switch and the second position trigger switch.

[0020] Preferably, the first position trigger switch, the second position trigger switch, the third position trigger switch, the fourth position trigger switch, and the fifth position trigger switch are distributed axially on the side of the volume tube, and each includes a photoelectric sensor suitable for monitoring the position of the piston.

[0021] Preferably, the volume tube is a cylindrical structure, and the volume tube includes a left circular cover plate and a right circular cover plate disposed at both ends of its axial direction. The first air port is disposed on the left circular cover plate, and the second air port is disposed on the right circular cover plate.

[0022] Preferably, the volume tube is made of stainless steel.

[0023] And / or, the length of the volume tube is between 280 mm and 320 mm.

[0024] And / or, the diameter of the volume tube is between 35 mm and 45 mm.

[0025] Preferably, the piston includes a piston body and a sealing ring fitted onto the piston body, the piston body being made of aluminum and the sealing ring being made of polytetrafluoroethylene.

[0026] Preferably, the first pipeline, the second pipeline, the valve one pipeline, the valve two pipeline, the pressure relief pipeline, and the check pipeline each include a gas hose suitable for conveying gas.

[0027] The working principle of this invention is as follows: The flow meter under test is connected in series to the first outlet of a two-position four-way solenoid valve. The gas to be tested enters the first pipeline through the first reversing port. Simultaneously, the second valve is opened, and the gas to be tested enters the interior of the volumetric tube through the second valve pipeline and the third outlet, keeping the piston in the initial position. Once the temperature, pressure, and flow rate inside the volumetric tube stabilize, the second valve is closed and the first valve is opened. The gas to be tested enters the volumetric tube through the first valve pipeline and the first outlet. The piston inside the volumetric tube moves from the initial position to the final position as pushed by the gas to be tested. When the piston passes through the first position, it triggers a switch and triggers a timer; when the piston passes through the second position, it triggers a switch and closes the timer. The movement time of the piston is measured. To address specific standard volumetric flow rate values, a formula for reproducing volumetric flow rate is introduced: It is understandable that the distance between the first and second position trigger switches is the piston's measuring stroke. Since both the measuring stroke and the cross-sectional area of ​​the volume tube are known data, the volume parameter V can be calculated from the formula, and the time parameter Δt can be obtained from the formula using a timer. The standard volumetric flow rate q can then be obtained by reproducing the volumetric flow rate formula. v The calculated gas flow rate is compared with the flow rate of the flow meter under test for verification.

[0028] The beneficial effects of this invention are:

[0029] This invention is applicable to the measurement of minute gas flow rates and has advantages such as pressure resistance, small calibrator size, low requirements for external environment, high accuracy, and high portability. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a pressure-resistant gas micro-flow calibrator provided by the present invention.

[0031] In the diagram, the components are: 1. Two-position four-way solenoid valve; 11. First air inlet; 12. First air outlet; 13. First reversing port; 14. Second reversing port; 2. Volume tube; 2. Fluid chamber; 21. Piston; 22. First air port; 23. Second air port; 24. Third air port; 25. Fourth air port; 26. Left circular cover plate; 27. Right circular cover plate; 28. First position trigger switch; 31. Second position trigger switch; 32. Third position trigger switch; 33. Fourth position trigger switch; 34. Fifth position trigger switch; 35. First pipeline; 41. Second pipeline; 42. Valve one pipeline; 43. First valve; 431. Valve two pipeline; 44. Second valve; 441. Pressure relief pipeline; 45. Pressure relief valve; 451. Check pipeline; 46. Check valve; 461. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0034] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] like Figure 1The aforementioned pressure-resistant gas micro-flow calibrator includes a two-position four-way solenoid valve 1, a volume tube 2, a first position trigger switch 31, a second position trigger switch 32, and a timer controlled by the first and second position trigger switches 31 and 32. The two-position four-way solenoid valve 1 includes a first inlet 11, a first outlet 12, a first reversing port 13, and a second reversing port 14. The gas to be tested is adapted to enter the two-position four-way solenoid valve 1 through the first inlet 11 and to exit the two-position four-way solenoid valve 1 through the first outlet 12. The volume tube 2 includes a fluid chamber 21, a piston 22, a first air port 23, a second air port 24, and a third air port 25, with the first air port 23 and the second air port 24 respectively located at the axial ends of the fluid chamber 21. The first reversing port 13 is connected to the volume tube 2 through the first pipeline 41, and the second reversing port 14 is connected to the volume tube 2 through the second pipeline 42. The first pipeline 41 is connected to the first air port 23 and the third air port 25 through the valve first pipeline 43 and the valve second pipeline 44 respectively. The valve first pipeline 43 and the valve second pipeline 44 are arranged in parallel.

[0036] The fluid chamber 21 includes an initial position and an ending position. A first position trigger switch 31 and a second position trigger switch 32 are located between the initial and ending positions. The gas to be tested is adapted to enter the fluid chamber 21 through the second air inlet and hold the piston 22 in the initial position. The gas to be tested is adapted to push the piston 22 from the initial position to the ending position through the first air inlet 11. During this process, when the piston 22 passes the first position trigger switch 31, the timer starts counting, and when the piston 22 passes the second position trigger switch 32, the timer stops counting.

[0037] In this embodiment, valve one pipeline 43 includes a first valve 431, which is adapted to control the connection between the two-position four-way solenoid valve and the first air port 23, and valve two pipeline 44 includes a second valve 441, which is adapted to control the connection between the two-position four-way solenoid valve and the second air port 24.

[0038] The working principle of this invention is as follows: The flow meter under test is connected in series to the first outlet 12 of a two-position four-way solenoid valve 1. The gas to be tested enters the first pipeline through the first reversing port 13. Simultaneously, the second valve 441 is opened, and the gas to be tested enters the interior of the volume tube 2 through the valve second pipeline 44 and the third gas port 25, keeping the piston 22 in its initial position. After the temperature, pressure, and flow rate in the volume tube 2 stabilize, the second valve 441 is closed, and the first valve 431 is opened. The gas to be tested enters the volume tube 2 through the valve first pipeline 43 and the first gas port 23. The piston 22 in the volume tube 2 moves from the initial position to the final position as pushed by the gas to be tested. When the piston 22 passes through the first position trigger switch 31, the timer is triggered; when the piston 22 passes through the second position trigger switch 32, the timer is turned off. The movement time of the piston 22 is measured. To solve the specific standard volumetric flow rate value, a formula for reproducing volumetric flow rate is introduced: It is understandable that the distance between the first position trigger switch 31 and the second position trigger switch 32 is the measuring stroke of the piston 22. Since the measuring stroke and the cross-sectional area of ​​the volume tube 2 are both known data, the volume parameter V in the formula can be calculated, and the time parameter Δt in the formula can be obtained through the timer. The standard volume flow rate qv can be obtained according to the formula for reproducing the volume flow rate. The calculated gas flow rate to be measured is compared with the flow rate of the flow meter under test for verification.

[0039] In this embodiment, a pressure relief pipeline 45 is provided in parallel with valve one pipeline 43 and valve two pipeline 44. The pressure relief pipeline 45 includes a pressure relief valve 451 and is connected to the first pipeline 41 and the third air port 25 respectively, which is suitable for maintaining the pressure stability of the entire device.

[0040] In this embodiment, a third position trigger switch 33 is provided between the second position trigger switch 32 and the termination position. A check valve 46 is connected in parallel to the second pipeline 42, and the check valve 46 includes a check valve 461. The volume tube 2 includes a fourth gas port 26, and the check valve 46 is connected to both the fourth gas port 26 and the second pipeline 42. When the piston 22 moves past the third position trigger switch 33, the check valve 461 opens, and the gas to be tested in the volume tube 2 can be discharged through the check valve 46. Further, the check valve 461 is a butterfly valve structure, and the check valve 461 includes a closing spring adapted to support the check valve 461 and keep it closed.

[0041] Furthermore, the first pipeline 41, the second pipeline 42, the valve one pipeline 43, the valve two pipeline 44, the pressure relief pipeline 45, and the check pipeline 46 each include a gas hose suitable for conveying gas.

[0042] In this embodiment, a fourth position trigger switch 34 and a fifth position trigger switch 35 are sequentially arranged between the first position trigger switch 31 and the second position trigger switch 32. The fourth position trigger switch 34 and the fifth position trigger switch 35 are used to monitor whether the movement state of the piston 22 is uniform. Further, the first position trigger switch 31, the second position trigger switch 32, the third position trigger switch 33, the fourth position trigger switch 34, and the fifth position trigger switch 35 are axially distributed on the side of the volume tube 2, and each includes a photoelectric sensor suitable for monitoring the position of the piston 22.

[0043] In this embodiment, to facilitate future measurements after the initial measurement, the reversing function of the two-position four-way solenoid valve 1 is employed, allowing gas to enter through the second gas port 24 and push the piston 22 back to its initial position. Specifically, by switching the flow direction of the two-position four-way solenoid valve 1, gas enters the second reversing port 14 through the first inlet port 11, and then sequentially enters the fluid chamber 21 through the second pipeline 42 and the second gas port 24. The gas pushes the piston 22 from the termination position back to the initial position. During this process, the first valve 431 opens and the second valve 441 closes. At this time, gas enters the first reversing port 13 of the two-position four-way solenoid valve 1 through the valve-first pipeline 43 and the first pipeline 41, and is further released through the first outlet port 12 of the two-position four-way solenoid valve 1.

[0044] In this embodiment, the volume tube 2 is a cylindrical structure with a length of 300 mm and a diameter of 40 mm. The volume tube 2 includes a left circular cover plate 27 and a right circular cover plate 28 disposed at its axial ends. A first air port 23 is disposed on the left circular cover plate 27, and a second air port 24 is disposed on the right circular cover plate 28. Further, the volume tube 2 is made of stainless steel, and the piston 22 includes a piston body and a sealing ring fitted onto the piston body. The piston body is made of aluminum, and the sealing ring is made of polytetrafluoroethylene (PTFE).

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A pressure-resistant gas micro-flow calibrator, characterized in that, include: A two-position four-way solenoid valve, suitable for connecting to the gas to be measured. A volume tube includes a fluid chamber, a piston, a first air port, a second air port, and a third air port. The first and second air ports are respectively located at opposite axial ends of the fluid chamber. The fluid chamber includes an initial position and a final position. The gas to be measured is adapted to enter the fluid chamber through the third air port and hold the piston in the initial position. A first position trigger switch and a second position trigger switch are both located between the initial position and the final position. The timer is controlled by the first position trigger switch and the second position trigger switch. The gas to be tested is adapted to enter the fluid cavity through the first gas port and push the piston from the initial position to the final position. During this process, when the piston passes the first position trigger switch, the timer starts timing, and when the piston passes the second position trigger switch, the timer stops timing.

2. The pressure-resistant gas micro-flow calibration instrument according to claim 1, characterized in that, It also includes a valve-1 pipeline and a valve-2 pipeline arranged in parallel. The valve-1 pipeline includes a first valve, which is adapted to control the connection between the two-position four-way solenoid valve and the first air port. The valve-2 pipeline includes a second valve, which is adapted to connect the two-position four-way solenoid valve and the second air port.

3. The pressure-resistant gas micro-flow calibration instrument according to claim 2, characterized in that, It also includes a first pipeline and a second pipeline. The two-position four-way solenoid valve includes a first air inlet, a first air outlet, a first reversing port and a second reversing port. The gas to be tested is adapted to enter the two-position four-way solenoid valve through the first air inlet and to flow out of the two-position four-way solenoid valve through the first air outlet. The first reversing port is connected to the valve one pipeline and the valve two pipeline through the first pipeline, respectively. The second reversing port is connected to the second air port through the second pipeline.

4. The pressure-resistant gas micro-flow calibration instrument according to claim 3, characterized in that, It also includes a pressure relief pipeline, which includes a pressure relief valve. The pressure relief pipeline is connected in parallel with the first valve pipeline and the second valve pipeline. The pressure relief pipeline is connected to the first pipeline and the third air port, respectively.

5. The pressure-resistant gas micro-flow calibration instrument according to claim 4, characterized in that, Also includes Check line, the check line including a check valve, A third position trigger switch is disposed between the second position trigger switch and the termination position. The volume tube includes a fourth gas port, and the check pipe is connected to the fourth gas port and the second pipe respectively. When the piston moves through the third position to trigger the switch, the check valve opens, and the gas to be tested in the volume tube can be discharged through the check pipe.

6. A pressure-resistant gas micro-flow calibrator according to claim 5, characterized in that, The check valve is a butterfly valve structure, and the check valve includes a closing spring, which is adapted to support the check valve to remain closed.

7. The pressure-resistant gas micro-flow calibration instrument according to claim 6, characterized in that, It also includes a fourth position trigger switch and a fifth position trigger switch suitable for monitoring the movement state of the piston, wherein the third position trigger switch and the fourth position trigger switch are disposed between the first position trigger switch and the second position trigger switch.

8. The pressure-resistant gas micro-flow calibration instrument according to any one of claims 1-7, characterized in that, The volume tube is a cylindrical structure, and the volume tube includes a left circular cover plate and a right circular cover plate disposed at both ends of its axial direction. The first air port is disposed on the left circular cover plate, and the second air port is disposed on the right circular cover plate.

9. A pressure-resistant gas micro-flow calibrator according to claim 8, characterized in that, The volume tube is made of stainless steel. And / or, the length of the volume tube is between 280 mm and 320 mm. And / or, the diameter of the volume tube is between 35 mm and 45 mm.

10. The pressure-resistant gas micro-flow calibration instrument of claim 1, wherein, The piston includes a piston body and a sealing ring fitted onto the piston body. The piston body is made of aluminum, and the sealing ring is made of polytetrafluoroethylene.

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