A gas meter air tightness testing device

Abstract

This invention discloses a gas meter airtightness testing device, specifically relating to the field of airtightness testing technology. It includes a test chamber, a standard gas meter, a gas meter under test, a pressurizing device, a valve assembly, and a pressure detection assembly. The valve assembly includes a pressure regulating valve, a venting valve, and a discharge valve. The gas outlet pipe of the standard gas meter is connected to the gas inlet pipe of the gas meter under test. The gas meter under test is placed in the test chamber. The venting valve is located on the connecting pipe of the gas outlet pipe of the gas meter under test. A leak detection assembly is also installed in the test chamber to detect whether there is gas leakage in the gas meter under test during the gradual cooling process of the test chamber. This invention can effectively simulate a low-temperature environment and test the airtightness of a diaphragm gas meter under low-temperature conditions. This allows for effective judgment of the actual quality of the diaphragm gas meter, providing more effective extreme characteristic testing data for diaphragm gas meters, which is beneficial for the continued research and design of diaphragm gas meters.

Description

Technical Field

[0001] This invention relates to the field of airtightness testing technology, and more specifically, to a gas meter airtightness testing device. Background Technology

[0002] A gas meter is a measuring device used to measure and record the amount of gas (such as natural gas, liquefied petroleum gas, etc.) used. Among them, the most widely used is the diaphragm gas meter. In the design and production process of gas meters, strict inspection standards must be followed to ensure design quality and production quality. In particular, more stringent testing is required during the design and improvement of gas meters. In order to prevent gas leakage, the gas meter needs to be accurately tested for air tightness. For the air tightness test of a gas meter under standard conditions, the testing principle is to fill the diaphragm gas meter with gas and increase the pressure to make the gas meter be in a high-pressure state higher than its actual operating pressure, and then observe whether there is any gas leakage.

[0003] Generally, gas meters operate within a temperature range of -10℃ to +40℃. However, in cold regions or under unexpected conditions (such as building heating failure or unexpected ventilation causing the gas meter to be at the same temperature as the outside environment), gas meters face more severe low-temperature environments. As the temperature drop affects the material properties of some structures in the gas meter (such as the sealing structure), the risk of gas meter leakage increases in low-temperature environments. Therefore, when designing and improving gas meters, it is necessary to ensure that the gas meter can maintain stable leak-proof characteristics in low-temperature environments. Consequently, conventional airtightness testing is difficult to provide effective test data on the actual quality of diaphragm gas meters, which is not conducive to judging the extreme characteristics of gas meter design and improvement. Summary of the Invention

[0004] The present invention provides a gas meter air tightness testing device, which aims to solve the problem that: in low temperature environments, the risk of leakage of diaphragm gas meters increases, and conventional air tightness testing is difficult to provide effective test data on the actual quality of diaphragm gas meters, which is not conducive to judging the extreme characteristics of the design and improvement of diaphragm gas meters.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a gas meter air tightness testing device, comprising a test chamber, a standard meter, a meter to be tested, a pressurizing device, a valve assembly, and a pressure testing assembly, wherein the valve assembly comprises a pressure regulating valve, a venting valve, and a drain valve, and the test chamber is equipped with a cooling device;

[0006] The pressurizing device is connected to the air inlet pipe of the standard gauge, the air outlet pipe of the standard gauge is connected to the air inlet pipe of the gauge under test, the gauge under test is placed in the test chamber, and the venting valve is set on the connecting pipe of the air outlet pipe of the gauge under test.

[0007] The test chamber is also equipped with a leak detection component, which is used to detect whether there is any gas leakage in the test instrument during the gradual cooling process inside the test chamber.

[0008] In a preferred embodiment, the test chamber is mounted on a testing frame, which is also equipped with a control testing platform for placing a standard meter. Fixing clamps are provided on both the control testing platform and inside the test chamber for fixing the diaphragm gas meter. A docking frame is also provided on both the control testing platform and inside the test chamber, and docking pipes that connect to the inlet pipe and outlet pipe respectively are installed on the docking frame. The docking frame is driven to move by a docking driver.

[0009] In a preferred embodiment, the fixing clamps are all driven to move by a linear drive device, so that after the standard meter and the meter to be tested are fixed on the outside, the fixing clamps are driven to move to the inside. The test chamber is provided with a door, and the door and the side wall of the test chamber are provided with heat insulation structure.

[0010] In a preferred embodiment, the air leakage detection component is an acoustic wave sensing air leakage detection component. The inner wall of the test chamber is also provided with a sound insulation structure. The acoustic wave sensing air leakage detection component is set in the test chamber and includes multiple sets of acoustic wave sensors and an acoustic imager evenly distributed in the test chamber. The acoustic imager is installed on the door of the chamber.

[0011] In a preferred embodiment, a pipe separation assembly is provided between the air inlet pipe of the meter under test and the air outlet pipe of the standard meter, and a first closed control valve and a second closed control valve are respectively provided on the pipes on both sides of the pipe separation assembly.

[0012] In a preferred embodiment, a partition box is provided at the rear of the test chamber on the testing frame. The pipe separation assembly and the docking frame are placed in the partition box. The test instrument and the docking frame are placed horizontally. A partition plate is provided between the test chamber and the partition box. The partition plate has an internal insulation structure. Both sets of docking pipes corresponding to the test instrument pass through the partition plate. A gap is provided between the partition plate and the docking pipes. A balanced bearing plate is provided at the bottom of the test chamber and the partition box. The balanced bearing plate is vertically slidably installed in the testing frame. The test instrument, the corresponding docking frame, and the docking driver are all installed on the balanced bearing plate.

[0013] In a preferred embodiment, the air leakage detection component is a gravity-sensing air leakage detection component, which includes a weighing plate, a balanced bearing plate fixedly connected to the weighing plate through a connecting structure, and the weighing plate connected to a weighing sensor.

[0014] In a preferred embodiment, a weighing beam is rotatably mounted on the testing frame, and an inverted frame is also fixedly mounted on the testing frame. The load cell is mounted on the inverted frame with its detection end facing downwards. The long arm end of the weighing beam contacts the bottom of the weighing plate, and the short wall end of the weighing beam contacts the detection end of the load cell.

[0015] In a preferred embodiment, a pressure regulating valve is installed on the pipeline between the pressurizing device and the standard gauge, and a drain valve is installed on the connecting pipeline between the outlet pipe of the standard gauge and the inlet pipe of the gauge under test. The pressure detection assembly includes an external pressure gauge and a built-in pressure gauge. The external pressure gauge is installed on the pipeline outside the test chamber, and the built-in pressure gauge is installed on the connecting pipe of the inlet pipe of the corresponding gauge under test.

[0016] In a preferred embodiment, the test chamber is provided with a cold air inlet pipe connected to a low-temperature air source, and the partition chamber is provided with an exhaust pipe and a hot air inlet pipe connected to a high-temperature air source. The low-temperature air source includes a first air pump and an air cooler, and the high-temperature air source includes a second air pump and an air heater.

[0017] The beneficial effects of this invention are as follows: This invention can effectively simulate a low-temperature environment and test the airtightness of a diaphragm gas meter under low-temperature conditions, thereby effectively judging the actual quality of the diaphragm gas meter and providing more effective extreme characteristic test data for the diaphragm gas meter. This is beneficial for the continued research and development and design of diaphragm gas meters. Moreover, by using a leak detection component to temporarily judge the leakage of the meter under test when the test chamber is cooled, the influence of the gas pressure change caused by the contraction of the gas inside the meter under test due to the cooling of the test chamber on the judgment of whether there is a leak can be eliminated, thereby improving the accuracy of judging the quality of the diaphragm gas meter and improving the test quality. Attached Figure Description

[0018] Figure 1 This is a complete pipeline diagram for testing according to Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the overall structure of the diaphragm gas meter tested in this invention.

[0020] Figure 3 This is a schematic diagram of the detection device of the present invention.

[0021] Figure 4 This is a schematic diagram of the detection state of the present invention.

[0022] Figure 5 This is a diagram showing the state of each connecting pipe in the two sets of connecting frames of the present invention when connected to the corresponding ports of the standard meter and the meter to be tested.

[0023] Figure 6 This is a diagram showing the state of the test instrument of the present invention being tested in a test chamber.

[0024] Figure 7 This is a complete pipeline diagram for testing according to Embodiment 2 of the present invention.

[0025] Figure 8 This is a schematic diagram showing the placement of the test instrument and the docking frame in Embodiment 2 of the present invention.

[0026] Figure 9 This is a top-view diagram of the test instrument during the cooling process of the test chamber in Embodiment 2 of the present invention.

[0027] Figure 10 This is a schematic diagram of the improved gravity-sensing leak detection component of the present invention.

[0028] Figure 11 This is a schematic diagram of the air supply principle in the test chamber and partition box of the present invention.

[0029] Figure 12 For the present invention Figure 10 Enlarged view of the structure of part A.

[0030] The attached diagram is labeled as follows: 1. Test chamber; 101. Chamber door; 102. Partition plate; 103. Cold air inlet pipe; 11. Testing frame; 12. Comparison testing table; 13. Fixing clamp; 131. Balance bearing plate; 14. Docking frame; 141. Docking driver; 15. Docking pipe; 16. Partition box; 161. Exhaust pipe; 162. Hot air inlet pipe; 17. Pipe separation assembly; 171. Separation pipe; 172. Separation moving seat; 173. Separation driver; 18. Low-temperature air source; 181. First air pump; 182. Air cooler; 19. High-temperature air source; 191. Second air pump. ; 192. Air heater; 2. Diaphragm gas meter; 201. Standard meter; 202. Meter to be tested; 21. Inlet pipe; 22. Outlet pipe; 3. Pressurization device; 4. Valve assembly; 41. Pressure regulating valve; 42. Venting valve; 43. Drain valve; 44. First closed control valve; 45. Second closed control valve; 5. Pressure detection assembly; 51. External pressure gauge; 52. Internal pressure gauge; 6. Leakage detection assembly; 61. Acoustic leakage detection assembly; 62. Gravity-sensing leakage detection assembly; 621. Weighing plate; 622. Weighing sensor; 623. Weighing beam; 624. Inverted frame. Detailed Implementation

[0031] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0032] Example 1, refer to the appendix of the instruction manual Figure 1A gas meter airtightness testing device includes a test chamber 1, a standard gas meter 201, a gas meter under test 202, a pressurizing device 3, a valve assembly 4, and a pressure detection assembly 5. The valve assembly 4 includes a pressure regulating valve 41, a venting valve 42, and a drain valve 43. Both the standard gas meter 201 and the gas meter under test 202 are diaphragm gas meters 2. Refer to the attached instruction manual for details. Figure 2 The standard meter 201 is a diaphragm gas meter 2 that has passed the test under normal temperature conditions, and is used as a reference for inspection. The diaphragm gas meter 2 is equipped with an inlet pipe 21 and an outlet pipe 22.

[0033] During testing, the test instrument 202 is placed in the test chamber 1, which is equipped with a cooling device to simulate a low-temperature environment, such as a refrigerator freezing device, or by introducing low-temperature gas into the test chamber 1 to achieve cooling. A temperature sensor is also installed in the test chamber 1 to stabilize the temperature inside the test chamber 1.

[0034] Of the above-mentioned devices, the instruction manual is attached. Figure 1 The pipelines shown are connected as follows: the pressurizing device 3 is connected to the air inlet pipe 21 of the standard gauge 201, and the air outlet pipe 22 of the standard gauge 201 is connected to the air inlet pipe 21 of the gauge under test 202. The gauge under test 202 is placed in the test chamber 1. The vent valve 42 is installed on the connecting pipeline of the air outlet pipe 22 of the gauge under test 202 to seal the entire pipeline. The pressure regulating valve 41 is installed on the pipeline between the pressurizing device 3 and the standard gauge 201 to regulate the overall pressure of the pipeline. The drain valve 43 is installed between the air outlet pipe 22 of the standard gauge 201 and the gauge under test 202. The gas inlet pipe 21 is connected to the gas inlet pipe 21, and the pressurizing device 3 is used to pressurize the entire pipeline. For example, a high-pressure air pump is used to gradually increase the pressure, and the pressure regulating valve 41 is used to regulate the pressure of the entire pipeline to stabilize it within the detection pressure range. In order to fully detect the quality of the gas meter 202, the actual detection pressure needs to be greater than its rated pressure value. For example, according to the design or research and development needs, the detection pressure is set to 1.5 times, 2 times or 3 times the rated pressure value of the gas meter, so as to ensure that the gas meter 202 is under high pressure during actual testing.

[0035] The pressure detection component 5 can be a pressure gauge to detect the overall pressure of the pipeline. In this embodiment, the pressure detection component 5 is an external pressure gauge 51, which is installed on the pipeline outside the test chamber 1, for example, on the pipeline between the standard gauge 201 and the pressurizing device 3.

[0036] For the airtightness test of diaphragm gas meters under normal conditions, the test standards and test methods described in section 6.2.1 of the national standard GB / T6968-2019 can be used to conduct a standardized airtightness test on the diaphragm gas meters. During the test, connect the gas inlet of the gas meter to the pressure regulating valve and pressure gauge, and connect it to a stabilizing gas source. Connect the gas outlet of the gas meter to the gate valve. During the test, according to the type test standard and the factory inspection standard, fill the gas meter with air or other gas and pressurize it to the test standard. Then, according to the change of the pressure gauge, determine whether the gas meter is leaking (if a leak occurs, the pressure value will decrease).

[0037] Based on the aforementioned basic detection principle, in this embodiment, during testing, nitrogen or other gases are introduced into the standard gauge 201 and the gauge under test 202 via the pressurizing device 3. After all the air inside the gauge under test 202 is replaced, the vent valve 42 is closed, and the gauge under test 202 is pressurized to the detection pressure value, creating a high-pressure state inside. Then, the test chamber 1 is cooled down to the detection temperature, for example, -10℃, -20℃, and -30℃, depending on actual needs. After the temperature decreases, it is kept constant for 30 minutes. Throughout the testing process, the pressure inside the gauge under test 202 is maintained at the detection pressure via the vent valve 43. If the gauge under test 202 leaks, the leakage rate of the gauge under test 202 under this low-temperature environment is measured by inspection. The leakage rate is recorded through continuous measurement, and the measurement time should not exceed 5 minutes. The leakage rate is the quotient of the amount of leaked nitrogen divided by the measurement time.

[0038] During actual testing, the test gauge 202 needs to be placed inside the test chamber 1. However, as the test chamber 1 is cooled down until the temperature reaches the testing temperature, the gas density decreases, and the gas pressure also decreases. Therefore, the pressure value of the pressure gauge will change accordingly during the actual cooling process. For the diaphragm gas meter in the design process, its actual quality is unknown. Therefore, slight leakage may occur during the cooling process. At this time, the pressure gauge is in a reduced state, making it difficult to accurately determine whether the diaphragm gas meter is leaking. This makes it impossible to achieve accurate product testing and is not conducive to effective analysis and improvement of the diaphragm gas meter. Therefore, in order to improve the testing effect, a leak detection component 6 is also installed inside the test chamber 1. The leak detection component 6 is used to detect whether the test gauge 202 has gas leakage during the gradual cooling process inside the test chamber 1.

[0039] During the cooling process of test chamber 1, the air pressure of the gauge under test 202 will also decrease due to the temperature drop. Therefore, the leak detection component 6 is used to determine whether there is any leak in the gauge under test 202 during the cooling process in test chamber 1. If no leak is detected, after the temperature in test chamber 1 is constant, the pressure value of the pipeline is detected by the pressure detection component 5. If the pressure of the pressure detection component 5 remains constant, it is determined that the gauge under test 202 will not leak in the corresponding low temperature environment. When a leak occurs, the pressure value of the pressure detection component 5 will change, and the leakage rate will be determined based on the change.

[0040] It should be noted that if the gas meter has an auxiliary device, the battery should be removed before the test. The test meter 202 should be tested using an empty gas meter casing provided by the manufacturer. Since the test meter 202 needs to be in a low temperature state, in order to avoid ice blockage inside the test meter 202, the gas supplied by the pressurizing device 3 needs to be dried before the test. When pressurizing, it is necessary to ensure that the original air in the test meter 202 has been fully discharged before closing the vent valve 42 and slowly pressurizing.

[0041] In the above scheme, refer to the appendix to the instruction manual. Figures 3 to 6 The test chamber 1 is set on the test frame 11, and the test frame 11 is also set on the reference test table 12. The reference test table 12 is used to place the standard meter 201. The reference test table 12 and the test chamber 1 are both equipped with fixing clamps 13. The fixing clamps 13 are used to fix the diaphragm gas meter 2 (the clamp structure is set according to the actual shape of the diaphragm gas meter 2, which will not be explained in detail in this embodiment). The reference test table 12 and the test chamber 1 are both equipped with docking frames 14. The docking frames 14 are equipped with connecting pipes 15 that are respectively connected to the inlet pipe 21 and the outlet pipe 22. All of the above pipelines are connected through the connecting pipes 15. The pressurizing device 3 and other devices can be placed in the test chamber 1. The docking frame 14 is driven to move by the docking driver 141 (such as a linear drive device such as a cylinder), and moves closer to or away from the diaphragm gas meter 2 by the drive of the docking driver 141.

[0042] Specifically, the connecting pipe 15 of the inlet pipe 21 of the standard meter 201 is connected to the pressurizing device 3 through a pipe, and the connecting pipe 15 of the outlet pipe 22 of the standard meter 201 is connected to the pipe corresponding to the inlet pipe 21 of the meter under test 202 through a pipe. The venting valve 42 is set on the connecting pipe 15 corresponding to the outlet pipe 22 of the meter under test 202, thereby completing the above-mentioned pipeline connection. During the test, it is only necessary to control the corresponding docking bracket 14 to move towards the standard meter 201 or the meter under test 202 to realize the docking of each connecting pipe 15 with the corresponding inlet pipe 21 and outlet pipe 22, so as to complete the pipeline connection and perform the above-mentioned test.

[0043] Refer to the instruction manual appendix Figure 4 and Figure 5In this embodiment, the standard meter 201 and the meter to be tested 202 can be placed vertically. In order to facilitate the placement of the standard meter 201 and the meter to be tested 202, the fixing clamp 13 is driven to move by a linear drive device. After the standard meter 201 and the meter to be tested 202 are fixed on the outside, the fixing clamp 13 is driven to move to the inside. The test chamber 1 is provided with a door 101. The door 101 and the side wall of the test chamber 1 are provided with heat preservation structure to ensure the simulation effect of the low temperature environment inside the test chamber 1.

[0044] In this embodiment, the leak detection component 6 is an acoustic wave sensing leak detection component 61. The inner wall of the test chamber 1 is also provided with a sound insulation structure. The acoustic wave sensing leak detection component 61 is installed in the test chamber 1 to collect the sound environment inside the test chamber 1. When the test chamber 1 is cooling down and the test gauge 202 does not leak, there is no sound wave generated inside the test chamber 1. When the acoustic wave sensing leak detection component 61 detects the sound wave, it is determined that the test gauge 202 has leaked during the cooling process. The acoustic wave sensing leak detection component 61 can use multiple sets of acoustic wave sensors evenly distributed in the test chamber 1, or it can use an acoustic imaging instrument (a new type of noise source identification, localization, and testing analysis system that can help people intuitively understand sound waves, sound fields, and sound sources, understand the location and cause of noise generated by machinery and equipment, and then find ways to control and manage noise) to determine whether there is a leak during the cooling process, but the cost is relatively high.

[0045] By adopting the above scheme, a low-temperature environment can be effectively simulated, and the airtightness of the diaphragm gas meter 2 under low-temperature conditions can be tested. This allows for an effective assessment of the actual quality of the diaphragm gas meter 2, which is beneficial for the continued research and development and design of the diaphragm gas meter 2. Furthermore, by using the leak detection component 6 to temporarily assess the leakage of the meter 202 under test during cooling in the test chamber 1, the influence of the pressure change caused by the contraction of the gas inside the meter 202 due to the cooling of the test chamber 1 on the assessment of whether there is a leak can be eliminated. This improves the accuracy of the assessment of the quality of the diaphragm gas meter 2 and enhances the quality of the test.

[0046] Example 2: In the above examples, sound waves are mainly used to detect whether there is a leak during the cooling process inside the test chamber 1. However, it is difficult to detect the amount of leakage during this process. Therefore, this example provides the following solution. Unlike the above examples, the leak detection component 6 is a gravity-sensing leak detection component 62. Since the internal air pressure of the gauge 202 is high and the amount of gas is large, when the internal air pressure of the gauge 202 is constant, its relative mass is also relatively stable. Therefore, by judging the relative weight change of the gauge 202 through a highly sensitive pressure sensor, it is possible to determine whether there is a leak. Furthermore, the amount of leakage can also be determined based on the amount of weight change.

[0047] Based on the above principles, please refer to the appendix to the instruction manual. Figure 7 This embodiment improves upon the detection principle of Embodiment 1 as follows: A pipe separation assembly 17 is provided between the air inlet pipe 21 of the gauge under test 202 and the air outlet pipe 22 of the standard gauge 201. A first closed control valve 44 and a second closed control valve 45 are respectively provided on the pipes on both sides of the pipe separation assembly 17. The gravity-sensing leakage detection assembly 62 is located below the gauge under test 202 and is used to weigh and judge the gauge under test 202. When the pressure of the pipeline system reaches the required level, the second closed control valve 45 and the first closed control valve 44 are closed when the test chamber 1 begins to cool down, and the pipe separation assembly 17 is disconnected, so that the gauge under test 202 forms a relatively independent unit in the test chamber 1, so that the gravity-sensing leakage detection assembly 62 can weigh it. After the test chamber 1 has cooled down, the pipe separation assembly 17 can be reconnected and the second closed control valve 45 and the first closed control valve 44 can be opened to restore the above-mentioned pipeline connection, and the pressure detection assembly 5 can continue to perform pressure detection on the entire pipeline.

[0048] It should be noted that when the pipeline separation assembly 17 is reconnected, the overall pressure of the pipeline will be balanced. At this time, the pressure of the test gauge 202 will decrease due to the temperature drop. Therefore, the pressure value of the external pressure gauge 51 will decrease temporarily. If no leakage occurs, the pressure detection of the external pressure gauge 51 will hardly change. If the detection value of the external pressure gauge 51 continues to decrease, it is determined that a leak has occurred. After a period of time after the pipeline separation assembly 17 is reconnected, the leakage rate will be judged after the pressure of the test gauge 202 and the standard gauge 201 is balanced.

[0049] Specifically, a partition box 16 is provided on the testing frame 11 at the rear of the test chamber 1. The pipe separation assembly 17 and the docking frame 14 are arranged in the partition box 16. In this embodiment, the gauge to be tested 202 and the docking frame 14 are placed horizontally. A partition plate 102 is provided between the test chamber 1 and the partition box 16. The partition plate 102 has an internal insulation structure. The two sets of connecting pipes 15 corresponding to the gauge to be tested 202 pass through the partition plate 102. In order to avoid the partition plate 102 from obstructing the connecting pipes 15, a gap is provided between the partition plate 102 and the connecting pipes 15. A balanced bearing plate 131 is provided at the bottom of the test chamber 1 and the partition box 16. The balanced bearing plate 131 is vertically slidably installed in the testing frame 11. The gauge to be tested 202 and the corresponding connecting pipe 15 are connected in the partition box 16. The docking frame 14 and docking driver 141 are both mounted on the equalization bearing plate 131. The equalization bearing plate 131 is connected to the gravity-sensing leakage detection component 62, so that the test gauge 202 and its corresponding structure can be placed relatively stably on the same equalization bearing plate 131. After the pipeline separation component 17 is separated, the individual system composed of the test gauge 202 and the docking frame 14 can be weighed and tested. If the system weight is constant, no leakage will occur during the cooling process. If the system weight decreases, leakage will occur. The amount of leakage during the cooling process can also be calculated based on the weight change. After the cooling is completed, in order to complete the comparison test with the standard gauge 201, the pipeline separation component 17 needs to be reconnected to restore the overall test pipeline.

[0050] Furthermore, refer to the appendix of the instruction manual in the above scheme. Figure 8 and Figure 9 The vent valve 42 is fixedly installed on the connecting pipe 15 of the vent pipe 22 of the corresponding meter 202. The first sealing control valve 44 is fixedly installed on the connecting pipe 15 of the inlet pipe 21 of the corresponding meter 202. The pipeline separation assembly 17 includes a separation pipe 171 and a separation moving seat 172. The separation pipe 171 is set to the connecting pipe 15 connected to the inlet pipe 21. The separation moving seat 172 is slidably installed in the partition box 16. The separation moving seat 172 is driven to move by the separation driver 173 (e.g., a linear drive device such as a cylinder). The second sealing control valve 45 is installed on the separation pipe 171. Thus, by driving the separation pipe 171 to move and connect or disconnect with the connecting pipe 15, the separation and reconnection of the pipeline separation assembly 17 can be realized.

[0051] The gravity-sensing leak detection component 62 includes a weighing plate 621, a weighing sensor 622 is provided at the bottom of the weighing plate 621, and a balanced support plate 131 is fixedly connected to the weighing plate 621 through a connecting structure. The weighing sensor 622 is used to determine the overall weight of the balanced support plate 131. The weighing sensor 622 is preferably a highly sensitive pressure sensor (such as a capacitive pressure sensor or a Hall element pressure sensor) to convert gravity into pressure on the sensor, thereby enabling weight detection.

[0052] Furthermore, since the density of gas is relatively low, the aforementioned weight change is relatively small. To facilitate detection and more effectively determine this change, a corresponding balance structure can be set up, for example, as shown in the appendix to the instruction manual. Figure 10 and Figure 12 A weighing beam 623 is rotatably mounted on the testing frame 11, and an inverted frame 624 is also fixedly mounted on the testing frame 11. A load cell 622 is mounted on the inverted frame 624 with its detection end facing downwards. The long arm of the weighing beam 623 contacts the bottom of the weighing plate 621, and the short arm of the weighing beam 623 contacts the detection end of the load cell 622. Thus, the weighing beam 623 forms a lever to amplify the pressure of the weighing plate 621 and transmit it to the load cell 622, thereby enabling a more accurate judgment of the weight change on the equalization bearing plate 131. In addition, a built-in pressure gauge 52 is also provided on the connecting pipe 15 corresponding to the air inlet pipe 21 of the gauge under test 202, which is used to detect the internal pressure value of the gauge under test 202 separately when the pipe separation component 17 is disconnected, so as to facilitate subsequent comparison and judgment.

[0053] In addition to amplifying the force using the load cell 622, it can also be used to measure substances such as butane or propane, or mixtures thereof, in the overall pipeline. These gases are gaseous at normal temperature and pressure, but can become liquid under pressure (similar to the fuel inside a lighter). When a leak occurs, the amount of liquid in the gauge 202 decreases, and the leaked substance reverts to gas due to the pressure drop, and will not remain on the gauge 202. Therefore, it is easier to determine the weight of the gauge 202.

[0054] Furthermore, because the air contains moisture, freezing can easily occur in the low-temperature environment inside test chamber 1, affecting the weighing effect of the gravity-sensing leak detection component 62. Therefore, it is necessary to dry the air inside test chamber 1, for example, by referring to the instructions attached to the manual. Figure 10 and Figure 11The test chamber 1 is equipped with a cold air inlet pipe 103, which is connected to a low-temperature air source 18. The partition box 16 is equipped with an exhaust pipe 161 and a hot air inlet pipe 162, which is connected to a high-temperature air source 19. The low-temperature air source 18 includes a first air pump 181 and an air cooler 182. The air cooler 182 is used to cool the air. After the air temperature inside the test chamber 1 is constant, the air is introduced into the test chamber 1. The air is also dried to ensure that the air inside the test chamber 1 is always dry. The high-temperature air source 19 includes a second air pump 181 and a second air cooler 182. Pump 191 and air heater 192 are used to heat the air. In order to avoid affecting the weighing of the gravity-sensing air leakage detection component 62, the partition plate 102 and the connecting pipe 15 and other corresponding structures are left with a gap. Excess air in the test chamber 1 flows into the partition box 16 through the gap and is discharged from the exhaust pipe 161. In order to avoid the corresponding valves and gauges in the partition box 16 being affected by low temperature, high temperature air is introduced into the partition box 16 by means of high temperature air source 19 to neutralize the low temperature air.

[0055] It should be noted that for the related equipment on the equalization load plate 131 that requires power supply and control, battery power supply and wireless control and wireless signal transmission should be used first, or flexible connection cables should be used, or line docking devices should be added to control the connection cables to be connected or disconnected when necessary.

[0056] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A gas meter airtightness testing device, characterized in that: The test chamber (1) includes a standard gauge (201), a gauge to be tested (202), a pressurizing device (3), a valve assembly (4) and a pressure detection assembly (5). The valve assembly (4) includes a pressure regulating valve (41), a venting valve (42) and a drain valve (43). The test chamber (1) is equipped with a cooling device. The pressurizing device (3) is connected to the air inlet pipe (21) of the standard meter (201), the air outlet pipe (22) of the standard meter (201) is connected to the air inlet pipe (21) of the meter to be tested (202), the meter to be tested (202) is placed in the test chamber (1), and the venting valve (42) is set on the connecting pipe of the air outlet pipe (22) of the meter to be tested (202); The test chamber (1) is also equipped with a leak detection component (6). The leak detection component (6) is used to detect whether there is gas leakage in the test instrument (202) during the gradual cooling process of the test chamber (1). The test chamber (1) is set on the test frame (11), and the test frame (11) is also set with a reference test stand (12). The reference test stand (12) is used to place the standard meter (201). Fixing clamps (13) are set on the reference test stand (12) and inside the test chamber (1). The fixing clamps (13) are used to fix the diaphragm gas meter (2). A docking frame (14) is set on the reference test stand (12) and inside the test chamber (1). A docking pipe (15) is installed on the docking frame (14) to dock with the inlet pipe (21) and the outlet pipe (22) respectively. The docking frame (14) is driven to move by the docking driver (141). A pipe separation assembly (17) is provided between the air inlet pipe (21) of the test instrument (202) and the air outlet pipe (22) of the standard instrument (201). A first closed control valve (44) and a second closed control valve (45) are respectively provided on the pipes on both sides of the pipe separation assembly (17). A partition box (16) is provided on the testing frame (11) behind the test chamber (1). The pipe separation assembly (17) and the docking frame (14) are placed in the partition box (16). The meter to be tested (202) and the docking frame (14) are placed horizontally. A partition plate (102) is provided between the test chamber (1) and the partition box (16). The partition plate (102) has an internal insulation structure. The two sets of connecting pipes (15) corresponding to the meter to be tested (202) are also provided. All penetrate the partition plate (102), and a gap is provided between the partition plate (102) and the connecting pipe (15). The bottom of the test chamber (1) and the partition box (16) is provided with a balanced bearing plate (131). The balanced bearing plate (131) is vertically slidably installed in the test frame (11). The test instrument (202) and the corresponding docking frame (14) and docking driver (141) of the test instrument (202) are all installed on the balanced bearing plate (131). The air leakage detection component (6) is a gravity-sensing air leakage detection component (62). The gravity-sensing air leakage detection component (62) includes a weighing plate (621). The equalization bearing plate (131) is fixedly connected to the weighing plate (621) through a connection structure. The weighing plate (621) is connected to a weighing sensor (622).

2. The gas meter airtightness testing device according to claim 1, characterized in that: The fixing clamps (13) are all driven to move by a linear drive device so that after the standard meter (201) and the meter to be tested (202) are fixed on the outside, the fixing clamps (13) can be driven to move to the depth. The test chamber (1) is provided with a door (101), and the door (101) and the side wall of the test chamber (1) are provided with heat insulation structures.

3. The gas meter airtightness testing device according to claim 2, characterized in that: The air leakage detection component (6) is an acoustic wave sensing air leakage detection component (61). The inner wall of the test chamber (1) is also provided with a sound insulation structure. The acoustic wave sensing air leakage detection component (61) is set in the test chamber (1). The acoustic wave sensing air leakage detection component (61) includes multiple sets of acoustic wave sensors and acoustic imagers evenly distributed in the test chamber (1). The acoustic imager is installed on the door (101).

4. The gas meter airtightness testing device according to claim 2, characterized in that: A weighing rod (623) is rotatably mounted on the testing frame (11). An inverted frame (624) is also fixedly mounted on the testing frame (11). The weighing sensor (622) is mounted on the inverted frame (624), with the detection end of the weighing sensor (622) facing downwards. The long arm end of the weighing rod (623) contacts the bottom of the weighing plate (621), and the short wall end of the weighing rod (623) contacts the detection end of the weighing sensor (622).

5. A gas meter airtightness testing device according to claim 4, characterized in that: The pressure regulating valve (41) is installed on the pipeline between the pressurizing device (3) and the standard gauge (201). The drain valve (43) is installed on the connecting pipeline between the outlet pipe (22) of the standard gauge (201) and the inlet pipe (21) of the gauge to be tested (202). The pressure detection component (5) includes an external pressure gauge (51) and a built-in pressure gauge (52). The external pressure gauge (51) is installed on the pipeline outside the test chamber (1). The built-in pressure gauge (52) is installed on the connecting pipe (15) of the inlet pipe (21) of the corresponding gauge to be tested (202).

6. The gas meter airtightness testing device according to claim 5, characterized in that: The test chamber (1) is equipped with a cold air inlet pipe (103), which is connected to a low-temperature air source (18). The partition box (16) is equipped with an exhaust pipe (161) and a hot air inlet pipe (162), which is connected to a high-temperature air source (19). The low-temperature air source (18) includes a first air pump (181) and an air cooler (182). The high-temperature air source (19) includes a second air pump (191) and an air heater (192).

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