An automatic device for the verification of dynamic and static volumetric gas capacities

Abstract

The utility model relates to the technical field of gas metering discloses a kind of dynamic and static volumetric gas capacity automatic verification device, including sealed container, the bottom of the sealed container is communicated with water storage tank by water pump, and is communicated with standard device and water storage tank respectively by first pneumatic valve, commutator in turn, the top of the sealed container is communicated with the clock bell jar type gas flow standard device of being examined, the sealed container is used to store water, this water pump is used to inject water to the inside of sealed container, first sensor, second sensor are respectively arranged in the starting point and the end point of the measuring volume section of the clock bell jar type gas flow standard device of being examined, they are respectively used to gather the position information that the bell jar body of clock bell jar type gas flow standard device of being examined reaches starting point, end point;The first sensor, second sensor, first pneumatic valve, water pump, commutator, clock bell jar type gas flow standard device of being examined, standard device are connected with processor.

Description

Technical Field

[0001] This utility model belongs to the technical field of gas metering, specifically relating to an automatic calibration device for dynamic and static volumetric gas capacity. Background Technology

[0002] The bell-type gas flow standard device is the main equipment for calibrating gas flow meters and also the standard device for gas flow in the low-pressure range. It is used by metrology institutions in various countries as the original standard for flow measurement. As the original standard realized based on the basic definition of flow, whether the measurement value can be accurately traced back to basic quantities such as length and time depends on whether the volume of the bell can be accurately measured. Since the bell discharges part of its volume of gas step by step from top to bottom, the key to verifying the volume of the bell is to perform step-by-step volume measurement of its effective measuring section.

[0003] Currently, the dimensional method is mostly used to measure the volume of bell jars. However, due to the high dimensional accuracy of the bell jar itself, the volume of gas discharged from the bell jar is directly related to the internal volume of the bell jar. Therefore, the outer diameter measurement methods such as the pi ruler method, laser tracking method, and outside micrometer method are indirect measurements. They must be combined with wall thickness measurement (for bell jars with constant liquid level) or measurement of the inner diameter of the bell jar liquid tank, the inner diameter of the liquid level compensation tank, and the diameter of the liquid level compensation column (for bell jars with changing liquid level). This introduces a large measurement uncertainty, resulting in low measurement accuracy. Furthermore, the entire process is mainly manual, leading to low measurement efficiency. At the same time, it requires a high level of professional skills from the measurement personnel, making it difficult to quickly popularize and apply, and thus failing to meet actual measurement needs. Summary of the Invention

[0004] This invention provides an automatic calibration device for dynamic and static volumetric gas capacity, which solves the technical problems of existing calibration methods that are mostly manual and have low measurement efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An automatic calibration device for dynamic and static volumetric gas capacity includes a sealed container. The bottom of the sealed container is connected to a water storage tank via a water pump, and sequentially connected to a standard and the water storage tank via a first pneumatic valve and a reversing device, respectively. The top of the sealed container is connected to a bell-shaped gas flow standard device under test. The sealed container is used to store water, and the water pump is used to inject water into the sealed container. A first sensor and a second sensor are respectively installed at the starting point and the ending point of the metering volume section of the tested bell-shaped gas flow standard device. They are used to collect the position information of the bell body of the tested bell-shaped gas flow standard device at the starting point and the ending point, respectively. The first sensor, the second sensor, the first pneumatic valve, the water pump, the commutator, the tested bell-shaped gas flow standard device, and the standard are all connected to the processor. The processor is also connected to the touch screen, which is used to display the test results.

[0006] Furthermore, one end of the commutator outlet is connected to the water storage tank via a return pipe, a second pneumatic valve is installed on the return pipe, and a third pneumatic valve is installed on the connecting pipe between the sealed container and the tested bell-shaped gas flow standard device. The standard device is also connected to a water storage tank, and a drain valve is installed on its connecting pipe.

[0007] Furthermore, it also includes a herringbone bracket, with the sealed container located at the top of the herringbone bracket, the commutator located in the middle of the herringbone bracket, and the standard and water storage tank located at the bottom of the herringbone bracket.

[0008] Furthermore, a temperature sensor and a humidity sensor are installed on the top of the sealed container, which are used to detect the temperature and humidity information of the gas inside the sealed container, respectively. An opening for indicating the set liquid level is provided on the side of the top of the sealed container, and an electromagnetic valve is provided at the opening, which is connected to the processor.

[0009] Furthermore, both the first and second sensors are configured as photoelectric sensors, with their detection ends facing the bell jar body.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. By cleverly connecting the bell-shaped gas flow standard device under test with the standard and water tank using a sealed container and a reversing device, and then setting an appropriate valve on the connecting pipeline, the automatic verification of the bell-shaped gas flow standard device under test can be completed through valve control. This helps to improve verification efficiency, increase calibration accuracy, and meet actual calibration needs. 2. The automatic calibration device of this utility model has low requirements for the operator's skills and can complete the calibration without much experience, making it easier for operators to get started and more practical. At the same time, based on the hardware structure of the automatic calibration device of this utility model and combined with the corresponding control process, a new calibration method can be realized, which does not need to consider humidity correction and has higher accuracy. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the overall structure of the removal standard device and water storage tank of this utility model. Figure 1 ; Figure 3 This is a schematic diagram of the overall structure of the removal standard device and water storage tank of this utility model. Figure 2 ; Among them, 1-Standard device (standard metal device), 2-Water storage tank, 3-Water pump, 4-Return pipe, 5-Reversing device, 6-Sealed container, 7-Solenoid valve, 8-Third pneumatic valve, 9-First pneumatic valve, 10-Second pneumatic valve, 11-Drain valve, 12-Manual valve, 13-Humidity sensor, 14-A-shaped bracket, 15-Temperature sensor. Detailed Implementation

[0012] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following embodiments, in conjunction with the accompanying drawings, specifically describe the automatic calibration device for dynamic and static volumetric gas capacity of this utility model. It should be noted that the description of these embodiments is for the purpose of helping to understand this utility model, but does not constitute a limitation on this utility model.

[0013] like Figure 1-3 As shown, this utility model provides an automatic dynamic and static volumetric gas capacity calibration device, including a sealed container 6 for storing water. The bottom of the sealed container 6 is connected to a water storage tank 2 via a water pump 3, and is sequentially connected to a standard device 1 and the water storage tank 2 via a first pneumatic valve 9 and a reversing device 5, respectively. The top of the sealed container 6 is connected to the bell-shaped gas flow standard device under test. The water pump 3 is used to inject water into the sealed container 5. A first sensor and a second sensor are respectively installed at the starting point and the ending point of the metering volume section of the bell-shaped gas flow standard device under test. They are used to collect the position information of the bell body of the bell-shaped gas flow standard device under test when it reaches the starting point and the ending point, respectively. The first sensor, the second sensor, the first pneumatic valve, the water pump 3, the commutator 5, the tested bell-shaped gas flow standard device, and the standard device 1 are all connected to the processor. The processor is also connected to the touch screen, which is used to display the test results.

[0014] In this way, the processor receives the position information collected by the first sensor, controls the commutator to switch the connecting pipe to the pipe where the standard is located, so that the water flowing out of the sealed container is drained into the standard. This continues until the processor receives the position information from the second sensor, then controls the commutator to switch the connecting pipe to the pipe where the water storage tank is located, or controls the first pneumatic valve to close. Then, the water volume inside the standard is compared with the volume corresponding to the metering volume segment of the tested bell-shaped gas flow standard device to achieve automatic calibration, and the result is displayed on the touch screen. At the same time, it can also count the number of pulses in the metering volume segment of the tested bell-shaped gas flow standard device to complete the pulse equivalent measurement. The operation process is very simple, requiring minimal operator intervention, which helps to improve operational efficiency and makes it more practical.

[0015] Specifically as follows: We can make a herringbone bracket 14, the upper part of which is a square frame structure and the lower part is a figure-eight structure. The sealed container 6 is placed on the top of the square frame structure of the herringbone bracket 14, the commutator is set in the middle of the square frame structure, and the standard device 1 and the water tank 2 are set in the hollow position of the figure-eight structure in the herringbone bracket 14. Of course, according to actual needs, the water tank 2 can also be placed next to the herringbone bracket.

[0016] A water pump 3 is installed at one end of the top of the water storage tank 2, and is connected to the sealed container 6 to inject water into the sealed container 6. The other end is open and can be connected to the outlet side of the reversing device 5 through a return pipe 4. A second pneumatic valve 10 can be installed on the return pipe 4, and it can also be connected to the standard device 1. A drain valve 11 is installed on the connecting pipe or at the bottom of the standard device 1, so that the water in the standard device 1 is discharged into the water storage tank 2. Of course, the water pump 3 can also be directly connected to the return pipe 4, and water can be injected into the sealed container 6 through the reversing device 5.

[0017] The other end of the outlet side of the commutator 5 is connected to the standard device 1, and its inlet side is connected to the bottom of the sealed container 6 through the first pneumatic valve 9. A manual valve 12 is also provided on the commutator 5. The flow rate of the water flowing through the commutator 5 can be adjusted by the manual valve 12 to keep it within a reasonable range.

[0018] The top of the sealed container 6 is connected to the bell-shaped gas flow standard device under test. A third pneumatic valve 8 is installed on its connecting pipe. A temperature sensor 15 and a humidity sensor 13 are also installed on its top. They are used to detect the temperature and humidity information of the gas inside the sealed container 6, respectively, so as to use the temperature and humidity correction during subsequent calibration.

[0019] Additionally, an opening indicating the set liquid level is provided on the side of the top of the sealed container 6. A solenoid valve is installed at this opening, and this valve is also connected to the processor. When water needs to be pumped into the sealed container 6 via the water pump 3, the solenoid valve 7 is opened. Once the water level inside the sealed container 6 exceeds the opening of the solenoid valve 7, it will automatically leak, indicating that the water level inside the sealed container 6 has reached the set level. Therefore, water injection can be stopped, and the solenoid valve 7 can be closed. Alternatively, a level gauge can be installed at a suitable location to detect the water level inside the sealed container.

[0020] Both the first and second sensors can be configured as photoelectric sensors, with their detection ends facing the bell jar under test. Once the bell jar under test passes the location where the first and second sensors are set, the detection light of the photoelectric sensors will be blocked, causing the first and second sensors to generate detection signals to reflect the position information of the bell jar under test. This serves as a start signal, causing the processor to begin recording the pulse signals emitted by the gas flow standard device of the bell jar under test, thereby calculating the number of pulses passing through the metering volume section for subsequent pulse equivalent measurement.

[0021] The basic process for calibration using the automatic dynamic and static volumetric gas capacity verification device of this invention is as follows: Assume the starting and ending positions of the measuring volume section of the bell-shaped gas flow standard device under test are a and b, respectively, where a is the lower contact point and b is the upper contact point. When the bell-shaped device is filled with gas, the exhaust valve is opened, and the gas is discharged from the bell-shaped device. The bell-shaped device begins to descend, passing contact a at its highest point, at which point the measuring volume begins. It then passes contact b, at which point the measuring volume ends. The gas volume V is the measured volume of this section. ab This refers to the volume that needs to be measured by this device; similarly, for a bell jar body with an encoder, when the bell jar body passes through segment ab and emits N pulses, the device can also measure the pulse equivalent K=V of the bell jar being measured. ab / N. To achieve the measurement objective, the gas volume measuring device needs to be traced back to a higher-level liquid volume standard, such as a standard metal volumetric instrument 1.

[0022] The specific process is as follows: (1) Store enough water in water tank 2 and leave it for a period of time. According to the temperature sensor, the temperature difference between the water temperature in water tank 2, the air temperature inside the bell jar being tested, and the liquid temperature in the bell jar being tested should not exceed 0.2℃.

[0023] (2) Confirm the measuring volume segment of the bell jar to be measured, and determine the starting point a and the ending point b of the measuring volume segment.

[0024] (3) Select a standard metal measuring instrument with the corresponding volume according to the volume of the measuring volume segment.

[0025] (4) Close the third pneumatic valve 8 on the upper side of the sealed container 6 connected to the bell-shaped gas flow standard device under test, and the first pneumatic valve 9 connected to the reversing device on the lower side of the sealed container; at the same time, open the solenoid valve 7 on the side of the sealed container 6 and the second pneumatic valve 10 on the lower side of the sealed container 6 for direct venting, then connect the water pump 3 to the pipeline where the second pneumatic valve 10 is located, connect the pipeline of the solenoid valve 7 to the water storage tank 2, start the water pump 3, start adding water, fill the sealed container 6 with the set amount of water, control the liquid level at the liquid level of the solenoid valve 7, and after the water level stabilizes, close the solenoid valve 7, the second pneumatic valve 10 and the water pump 3, and open the third pneumatic valve 8.

[0026] (5) Inflate the bell jar under test with ambient air to raise the bell jar above contact point a. Connect the air outlet of the bell jar under test to the pneumatic valve 8. Try to minimize the gas volume of the connection section between the bell jar and the sealed container 6. Open the air outlet valve of the bell jar under test to connect the bell jar with the upper space of the sealed container 7. Then adjust the manual valve 12 of the reversing device 5 to make the water flow within a reasonable range and wait until the bell jar stabilizes.

[0027] (6) Start the test Dynamic method: Close the lower drain valve 11 of the standard metal measuring vessel 1, open the first pneumatic valve 9, and the water in the sealed container 6 flows to the return pipe 4 through the reversing device 5. The bell jar slowly descends, passing through contact a, and collects the signal emitted by the first sensor, controlling the reversing device 5 to redirect the water flow to the standard metal measuring vessel 1. At this time, the bell jar continues to descend, and the flow is recorded. —The saturated vapor pressure of the gaseous medium under the current conditions, —Relative humidity inside the sealed container —Relative humidity inside the bell jar, —Current atmospheric pressure, —The pressure inside the bell jar; when it drops to contact point b, the signal from the second sensor is collected, and the commutator 5 is controlled to switch back to the return pipe 4. The water is then introduced into the water storage tank through the return pipe. After the calibration is completed, the first pneumatic valve 9 is closed.

[0028] Static Method: Open the first pneumatic valve 9. Water in the sealed container 6 flows through the reversing device 5 to the return pipe 4. The bell slowly descends, passing through contact a, and the signal from the first sensor is collected. This controls the reversing device 5 to redirect the water flow to the standard metal measuring vessel 1. Simultaneously, the first pneumatic valve 9 is closed, stopping the water flow. The lower drain valve 11 of the standard metal measuring vessel is also closed. Opening the first pneumatic valve 9 again restarts the water flow, directing it to the standard metal measuring vessel 1 via the reversing device. The bell slowly descends, and the flow is recorded. —The saturated vapor pressure of the gaseous medium under the current conditions, —Relative humidity inside the sealed container —Relative humidity inside the bell jar, —Current atmospheric pressure, —The pressure inside the bell jar; when it drops to contact point b, the signal from the second sensor is collected, the first pneumatic valve 9 is closed, and the water flow stops.

[0029] (7) Read the volume value V of the standard metal measuring instrument 1. si The device records the number N pulses emitted by the encoder contacts from point a to point b. i Open the drain valve 11 to empty the standard metal measuring instrument 1 and complete the first calibration.

[0030] (8) Repeat the test n (n≥6) times according to the procedure described in steps (6) to (7).

[0031] Calculate the humidity correction factor In the formula: —The saturated vapor pressure of the gaseous medium under the current conditions; —Relative humidity inside the sealed container (read from 13); —Relative humidity inside the bell jar; —Current atmospheric pressure; —The internal pressure of the bell jar; Standard volume: In the formula: —No. Standard volume for the next test; —No. The volume is then verified by reading from a standard measuring instrument. , , —These are the coefficients of linear expansion for the scale, bell jar, and standard measuring instrument, respectively; —No. The temperature of the gas inside the bell jar measured during the second verification; —No. The humidity correction factor obtained from the second verification.

[0032] like It can be considered .

[0033] Encoder pulse equivalent : In the formula: —No. Encoder equivalent of the second calibration; —No. The number of pulses tested.

[0034] Standard volume average : Encoder pulse equivalent average value : The above calibration method can be used not only to calibrate the gas flow standard device under test, but also to calibrate the volume tube. The specific calibration steps are similar to those of the bell-type gas flow standard device.

[0035] Since the gas medium used in the above method is air refilled into the bell jar from the atmosphere (with atmospheric humidity), and the humidity of the two is different, the gas has a higher humidity after entering the sealed container with water from the bell jar, resulting in an increase in gas volume. Therefore, under the premise that the temperature difference is not significant, it is only necessary to correct for the effect of humidity on gas volume. For this reason, the calibration device of this utility model can also perform a new calibration method that can complete the calibration without correction, as follows: (1) Steps (1) to (4) are the same as the above method.

[0036] (5) Inflate the bell jar under test with ambient air to raise the bell jar above contact point a, then connect the outlet of the bell jar under test to the third pneumatic valve 8 to ensure that the gas volume of the connection section between the bell jar and the sealed container is as small as possible, and open the outlet valve of the bell jar under test to connect the bell jar with the upper space of the sealed container. Adjust the manual valve 12 on the reversing device to ensure the water flow rate is within a reasonable range. Open the first pneumatic valve 9, and the water in the sealed container begins to flow down. At the same time, the bell jar begins to descend. At this point, the reversing device 5 guides the water flow direction through the return pipe 4 to continuously guide the water into the water storage tank 2 until the bell jar is at its lowest point and the internal air is minimal. Close the first pneumatic valve 9 to stop the water discharge and maintain this position for a period of time.

[0037] Since the original gas inside the bell jar being tested has entered the sealed container, which contains water, the humidity of all gases in the pipeline reaches 100% RH. When the gas expands from a relatively dry humidity to 100% RH, the volume expands. By repeatedly using these gases to calibrate the volume of the bell jar, and waiting for a period of time, the humidity of all gases in the pipeline can reach 100% RH.

[0038] (6) Open the water pump 3 and the second pneumatic valve 10 to refill the sealed container 6 with a certain amount of water. After the water enters the sealed container, it occupies the volume and presses the gas above the water level back into the bell jar. At this time, the bell jar slowly rises until it rises to the initial position (above the a contact point). Then, close the second pneumatic valve 10 and the water pump 3 in sequence. At this time, the gas inside the bell jar being tested is full of humidity. Wait until the bell jar stabilizes.

[0039] (7) Start the test Dynamic method: Close the drain valve 11 at the lower end of the standard metal measuring instrument, open the first pneumatic valve 9, and the water in the sealed container 6 flows through the reversing device 5 to the return pipe 4 and then into the water storage tank. The bell slowly descends, passes through contact a, and collects the signal emitted by the first sensor, controlling the reversing device 5 to redirect the water flow to the standard metal measuring instrument 1; at this time, the bell continues to descend, and when it reaches contact b, it collects the signal emitted by the second sensor, controlling the reversing device 5 to redirect the flow back to the return pipe 4, and the water is again introduced into the water storage tank through the return pipe. After the calibration is completed, close the first pneumatic valve 9.

[0040] Static method: Open the first pneumatic valve 9, and the water in the sealed container 6 flows to the return pipe 4 through the reversing device 5. The bell slowly descends, passes through contact a, and collects the signal from the first sensor. It controls the reversing device 5 to redirect the water flow to the standard metal measuring vessel 1. At the same time, the first pneumatic valve 9 is closed, and the water flow stops. Then, the drain valve 11 at the lower end of the standard metal measuring vessel is closed, and the first pneumatic valve 9 is opened again. The water flow restarts, and the water flow is directed to the standard metal measuring vessel 1 by the reversing device. The bell slowly descends, and when it reaches contact b, it collects the signal from the second sensor. The first pneumatic valve 9 is then closed, and the water flow stops.

[0041] (8) Read the volume value V of the standard metal measuring instrument 1. si The number N of pulses emitted by the bell encoder from contact a to contact b is recorded. i Then open the drain valve 11 to empty the standard metal measuring instrument 1 and complete the first calibration.

[0042] (9) Repeat the test n (n≥6) times according to the procedure described in steps (7) to (8).

[0043] (10) Calculate the standard volume: In the formula: —No. Standard volume for the next test; —No. The volume is then verified by reading from a standard measuring instrument. , , —These are the coefficients of linear expansion for the scale, bell jar, and standard measuring instrument, respectively; —No. The temperature of the gas inside the bell jar measured during the second verification; like It can be considered .

[0044] Encoder pulse equivalent : In the formula: —No. Encoder equivalent of the second calibration; —No. The number of pulses tested.

[0045] Standard volume average : Encoder pulse equivalent average value : It is important to note that the schemes and arrangements of this application shown in the exemplary embodiments are merely exemplary. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible without substantially departing from the novel teachings and advantages of the subject matter described in this application (e.g., variations in various parameter values ​​(temperature, power, humidity, etc.), installation arrangements, names, colors, logical orders, etc.). Therefore, all such modifications are also included within the scope of this invention, and the order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "apparatus plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of this invention. Therefore, this invention is not limited to the particular embodiments but extends to various modifications that still fall within the scope of the appended claims.

[0046] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the present invention as currently considered, or those features that are not relevant to implementing the present invention) may be omitted.

[0047] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model 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 solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An automatic calibration device for dynamic and static volumetric gas capacity, characterized in that: The device includes a sealed container. The bottom of the sealed container is connected to a water storage tank via a water pump, and sequentially connected to a standard and the water storage tank via a first pneumatic valve and a reversing device, respectively. The top of the sealed container is connected to the bell-shaped gas flow standard device under test. The sealed container is used to store water, and the water pump is used to inject water into the sealed container. A first sensor and a second sensor are respectively installed at the starting point and the ending point of the metering volume section of the tested bell-shaped gas flow standard device. They are used to collect the position information of the bell body of the tested bell-shaped gas flow standard device at the starting point and the ending point, respectively. The first sensor, the second sensor, the first pneumatic valve, the water pump, the commutator, the tested bell-shaped gas flow standard device, and the standard are all connected to the processor. The processor is also connected to the touch screen, which is used to display the test results.

2. The automatic calibration device for dynamic and static volumetric gas capacity according to claim 1, characterized in that: One end of the commutator outlet is connected to the water storage tank via a return pipe. A second pneumatic valve is installed on the return pipe, and a third pneumatic valve is installed on the connecting pipe between the sealed container and the bell-shaped gas flow standard device under test. The standard device is also connected to a water storage tank, and a drain valve is installed on its connecting pipe.

3. The automatic calibration device for dynamic and static volumetric gas capacity according to claim 2, characterized in that: It also includes a herringbone bracket, with the sealed container located at the top of the herringbone bracket, the commutator located in the middle of the herringbone bracket, and the standard and water tank located at the bottom of the herringbone bracket.

4. The automatic calibration device for dynamic and static volumetric gas capacity according to claim 3, characterized in that: A temperature sensor and a humidity sensor are installed on the top of the sealed container. These sensors are used to detect the temperature and humidity of the gas inside the sealed container, respectively. An opening for indicating the set liquid level is provided on the side of the top of the sealed container, and an electromagnetic valve is provided at the opening, which is connected to the processor.

5. The automatic calibration device for dynamic and static volumetric gas capacity according to claim 1, characterized in that: Both the first and second sensors are photoelectric sensors, with their detection ends facing the bell body.

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