Gas tightness detection device for gas meter

Abstract

The invention discloses a gas meter airtightness detection device, and particularly relates to the technical field of airtightness detection, the gas meter airtightness detection device comprises a test box, a standard meter, a to-be-detected meter, a pressurization device, a valve assembly and a pressure detection assembly, the valve assembly comprises a pressure regulating valve, a deflation valve and a discharge valve, a gas outlet pipe of the standard meter is in butt joint with a gas inlet pipe of the to-be-detected meter, and the to-be-detected meter is arranged in the test box; the air release valve is arranged on a butt joint pipeline of an air outlet pipe of the to-be-tested meter, and an air leakage detection assembly is further arranged in the test box and used for detecting whether the to-be-tested meter leaks air or not in the process that the test box is gradually cooled. The low-temperature environment can be effectively simulated, the gas tightness of the diaphragm gas meter in the low-temperature environment can be tested, the actual quality of the diaphragm gas meter can be effectively judged, more effective limit characteristic detection data are provided for the diaphragm gas meter, and continuous research, development and design of the diaphragm gas meter are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of air tightness detection, and more particularly to an air tightness detection device for a gas meter. Background Art

[0002] A gas meter is a metering 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. During the design and production process of the gas meter, strict inspection standards need to be followed to ensure the design quality and production quality. In particular, during the design and improvement process of the gas meter, more rigorous testing is required. Among them, in order to prevent gas leakage, the gas meter needs to be accurately tested for air tightness. For the air tightness test of the gas meter under standard conditions, the detection principle is to fill the diaphragm gas meter with gas and increase the pressure so that the gas meter is in a high-pressure state higher than its actual use pressure, and then observe whether there is gas leakage.

[0003] Generally speaking, the operating temperature range of gas meters is between -10℃ and +40℃. However, in some cold areas or unexpected situations (such as building heating failure or accidental ventilation of the building causing the gas meter to be at the same temperature as the external low-temperature environment), the gas meter will face a more severe low-temperature environment. Since 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 will increase in low-temperature environments. Therefore, in the face of such situations, when designing and improving gas meters, it is necessary to ensure that the gas meter can still maintain stable anti-leakage characteristics in low-temperature environments. Therefore, conventional airtightness testing is difficult to provide effective test data for the actual quality of diaphragm gas meters, which is not conducive to judging the extreme characteristics of the design and improvement of gas meters. Summary of the Invention

[0004] The present invention provides a gas meter air tightness detection device to solve the problem that the risk of leakage of diaphragm gas meters increases in low-temperature environments, while conventional air tightness detection is difficult to provide effective detection data on the actual quality of diaphragm gas meters, which is not conducive to the design and improvement of diaphragm gas meters and the judgment of their limit characteristics.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a gas meter air tightness detection device, comprising a test chamber, a standard meter, a meter to be tested, a pressurizing device, a valve assembly and a pressure detection assembly, the valve assembly comprising a pressure regulating valve, a vent valve and a drain valve, and a cooling device provided in the test chamber; The pressurizing device is connected to the air inlet pipe of the standard meter, and the air outlet pipe of the standard meter is connected to the air inlet pipe of the meter to be tested. The meter to be tested is placed in the test chamber, and the air release valve is set on the connecting pipe of the air outlet pipe of the meter to be tested; The test chamber is also provided with a gas leakage detection component, which is used to detect whether there is gas leakage in the meter to be tested when the test chamber is gradually cooled down.

[0006] In a preferred embodiment, the test box is arranged on a detection rack, and a control detection table is also arranged on the detection rack. The control detection table is used to place the standard meter. Fixing fixtures are provided on the control detection table and in the test box. The fixing fixtures are used to fix the diaphragm gas meter. A docking frame is provided on the control detection table and in the test box. The docking frame is installed with docking tubes that dock with the air inlet pipe and the air outlet pipe respectively. The docking frame is driven to move by a docking driver.

[0007] In a preferred embodiment, the fixing fixtures are 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 fixtures are driven to move to a deep position, and a box door is provided on the test box, and an insulation structure is provided in the box door and the side walls of the test box.

[0008] In a preferred embodiment, the air leakage detection component is an acoustic wave sensing air leakage detection component, and a sound insulation structure is also provided on the inner wall of the test box. The acoustic wave sensing air leakage detection component is arranged in the test box. The acoustic wave sensing air leakage detection component includes multiple groups of acoustic wave sensors and acoustic imagers evenly distributed in the test box, and the acoustic imager is installed on the box door.

[0009] In a preferred embodiment, a pipeline separation component is provided between the air inlet pipe of the meter to be tested and the air outlet pipe of the standard meter, and the pipelines on both sides of the pipeline separation component are respectively provided with a first closed control valve and a second closed control valve.

[0010] In a preferred embodiment, a partition box is provided on the detection rack at the rear position of the test box, the pipe separation assembly and the docking frame are provided in the partition box, the meter to be tested and the docking frame are placed horizontally, a partition board is provided between the test box and the partition box, an insulation structure is provided inside the partition board, two sets of docking pipes corresponding to the meter to be tested pass through the partition board, and a gap is provided between the partition board and the docking pipes, a balancing load-bearing plate is provided at the bottom of the test box and the partition box, the balancing load-bearing plate is vertically slidably installed in the detection rack, the meter to be tested and the docking frame and docking driver corresponding to the meter to be tested are all installed on the balancing load-bearing plate.

[0011] In a preferred embodiment, the air leakage detection assembly is a gravity-sensing air leakage detection assembly, which includes a weighing plate, a balancing load-bearing plate fixedly connected to the weighing plate via a connecting structure, and the weighing plate is connected to a weighing sensor.

[0012] In a preferred embodiment, a weighing beam is rotatably mounted on the detection frame, an inverted frame is also fixedly mounted on the detection frame, a weighing sensor is mounted on the inverted frame, and the detection end of the weighing sensor is set downward, 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 weighing sensor.

[0013] In a preferred embodiment, the pressure regulating valve is arranged on the pipeline between the pressurizing device and the standard meter, the drain valve is arranged on the connecting pipeline between the outlet pipe of the standard meter and the inlet pipe of the meter to be tested, and the pressure detection component includes an external pressure gauge and a built-in pressure gauge. The external pressure gauge is arranged on the pipeline outside the test box, and the built-in pressure gauge is arranged on the connecting pipe of the inlet pipe corresponding to the meter to be tested.

[0014] In a preferred embodiment, a cold air inlet pipe is provided in the test box, which is connected to a low-temperature air source. An exhaust pipe and a hot air inlet pipe are provided in the partition box, which is 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.

[0015] The beneficial effects of the present invention are: the present invention can effectively simulate a low-temperature environment and test the air tightness of the diaphragm gas meter in a low-temperature environment, thereby being able to effectively judge the actual quality of the diaphragm gas meter, providing the diaphragm gas meter with more effective limit characteristic detection data, which is beneficial to the continued research and development and design of the diaphragm gas meter. Moreover, by temporarily judging the leakage of the meter to be tested with the help of the leakage detection component when the temperature is lowered in the test chamber, the influence of the pressure change caused by the contraction of the gas inside the meter to be tested due to the cooling of the test chamber on the judgment of whether there is a leak can be eliminated, thereby improving the judgment accuracy of the quality of the diaphragm gas meter and improving the detection quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a complete pipeline diagram for detection of embodiment 1 of the present invention.

[0017] Figure 2 This is a schematic diagram of the overall structure of the diaphragm gas meter tested in the present invention.

[0018] Figure 3 Schematic diagram of the detection device of the present invention.

[0019] Figure 4 It is a detection state schematic diagram of the present invention.

[0020] Figure 5 This is a state diagram of the two sets of docking frames of the present invention when the docking pipes are docked with the corresponding pipe openings of the standard meter and the meter to be tested.

[0021] Figure 6 This is a state diagram of the meter under test being tested in the test box according to the present invention.

[0022] Figure 7 This is a complete pipeline diagram for detection of embodiment 2 of the present invention.

[0023] Figure 8 This is a schematic diagram of the placement status of the meter to be tested and the docking frame in the second embodiment of the present invention.

[0024] Figure 9 This is a top view of the table under test during the cooling process of the test chamber in Example 2 of the present invention.

[0025] Figure 10 This is a schematic diagram of the structure of the improved gravity-sensing air leakage detection component of the present invention.

[0026] Figure 11 This is a schematic diagram of the air supply principle in the test box and partition box of the present invention.

[0027] Figure 12 For the present invention Figure 10 A magnified view of the structure of part A.

[0028] The accompanying drawings are marked as follows: 1. test chamber; 101. chamber door; 102. partition board; 103. cold air inlet pipe; 11. test rack; 12. control test table; 13. fixing fixture; 131. balanced load-bearing plate; 14. docking frame; 141. docking drive; 15. docking pipe; 16. partition box; 161. exhaust pipe; 162. hot air inlet pipe; 17. pipe separation assembly; 171. separation pipe; 172. separation movable seat; 173. separation drive; 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. Pressurizing device;4. Valve assembly;41. Pressure regulating valve;42. Release 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 wave sensing leakage detection assembly;62. Gravity sensing leakage detection assembly;621. Weighing plate;622. Weighing sensor;623. Weighing rod;624. Inverted frame. DETAILED DESCRIPTION

[0029] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0030] Example 1, refer to the attached Figure 1A gas meter air tightness detection device includes a test box 1, a standard meter 201, a meter 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 vent valve 42 and a drain valve 43. The standard meter 201 and the meter to be tested 202 are both diaphragm gas meters 2. Figure 2 The standard meter 201 is a diaphragm gas meter 2 that has passed the inspection at room temperature and is used as a reference for inspection. The diaphragm gas meter 2 is provided with an air inlet pipe 21 and an air outlet pipe 22.

[0031] During testing, the meter to be tested 202 is placed in a test box 1, which is equipped with a cooling device to simulate a low-temperature environment. For example, by referring to a refrigerator freezer, or by inputting low-temperature gas into the test box 1 to achieve cooling, a temperature sensor is provided in the test box 1 to stabilize the temperature inside the test box 1.

[0032] In the above device, the instructions are attached. Figure 1 The pipeline shown is connected, that is, 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 box 1, the air release valve 42 is set on the connecting pipeline of the air outlet pipe 22 of the meter to be tested 202, and is used to close the entire pipeline. The pressure regulating valve 41 is set on the pipeline between the pressurizing device 3 and the standard meter 201, and is used to adjust the overall pressure of the pipeline. The drain valve 43 is set on the air outlet pipe 22 of the standard meter 201 and the meter to be tested 202 The pressure increasing device 3 is used to pressurize the entire pipeline, for example, by using a high-pressure air pump to gradually increase the pressure, and cooperates with the pressure regulating valve 41 to regulate the pressure of the entire pipeline so that it is stable within the detection pressure value range. In order to fully detect the quality of the meter 202 to be tested, the actual detection pressure needs to be greater than the rated pressure value of the gas meter. For example, according to 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 meter 202 to be tested is in a high-pressure state during actual detection.

[0033] The pressure detection component 5 can use 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 arranged on the pipeline outside the test box 1, for example, on the pipeline between the standard gauge 201 and the pressurizing device 3.

[0034] For the air tightness test of the diaphragm gas meter under normal conditions, you can refer to the test standards and test methods recorded in Section 6.2.1 of the national standard GB / T6968-2019 to conduct standardized sealing tests on the diaphragm gas meter. During the test, connect the air inlet of the gas meter to be tested to the pressure regulating valve and the pressure gauge, and connect to the pressure-stabilized gas source. Connect the gas outlet to the gate valve. During the test, fill the gas meter with air or other gas according to the type inspection standards and factory inspection standards, and pressurize it to the inspection standard. Then, judge whether the gas meter is leaking based on the changes in the pressure gauge (if a leak occurs, the pressure value will decrease).

[0035] Based on the above basic detection principle, during testing, this embodiment introduces nitrogen or other gas into the standard meter 201 and the meter under test 202 via the pressurizing device 3. After all the air inside the meter under test 202 is replaced, the bleed valve 42 is closed and the meter under test 202 is pressurized to the test pressure value, causing its interior to be in a high-pressure state. The test chamber 1 is then cooled to the test temperature. For example, depending on actual needs, the temperature can be tested at -10°C, -20°C, and -30°C. After the temperature is lowered, it is maintained constant for 30 minutes. Throughout the testing process, the pressure inside the meter under test 202 is maintained at the test pressure via the bleed valve 43. If the meter under test 202 leaks, the leakage rate of the meter under test 202 in this low-temperature environment is measured by inspection. The leakage rate is recorded continuously, and the measurement time should not exceed 5 minutes. The leakage rate is the quotient of the amount of nitrogen leakage measured divided by the measurement time.

[0036] During the actual test, the meter to be tested 202 needs to be placed in the test box 1. However, when the test box 1 is cooled down until the temperature drops to the detection temperature, as the gas temperature decreases, the gas density decreases and the gas pressure also decreases. Therefore, during the actual cooling process, the pressure value of the pressure gauge will also change accordingly. For the diaphragm gas meter in the design process, its actual quality is in an unknown state. Therefore, during the cooling process, slight leakage may also occur. At this time, the pressure gauge is in a reduced state, and it is difficult to accurately determine whether the diaphragm gas meter is leaking. Accurate detection of the product cannot be achieved, which is not conducive to effective analysis and improvement of the diaphragm gas meter. Therefore, in order to improve the detection effect, a gas leakage detection component 6 is also provided in the test box 1. The gas leakage detection component 6 is used to detect whether there is gas leakage in the meter to be tested 202 inside the test box 1 during the gradual cooling of the test box 1.

[0037] Among them, since the temperature of the meter to be tested 202 decreases during the cooling process of the test chamber 1, the air pressure will also decrease. Therefore, the leakage detection component 6 is used to judge whether the meter to be tested 202 is leaking during the cooling process in the test chamber 1. If it is judged that no leakage occurs, after the temperature in the test chamber 1 is constant, the pipeline pressure value is detected by the pressure detection component 5. If the subsequent pressure of the pressure detection component 5 is constant, it is determined that the meter to be tested 202 will not leak in the corresponding low temperature environment. When a leakage occurs, the pressure value of the pressure detection component 5 will change, and then the leakage rate is judged according to the change.

[0038] It should be noted that if it is a gas meter with additional devices, the battery should be removed before the test, and the meter to be tested 202 should be tested using the empty shell of the gas meter provided by the manufacturer. Since the meter to be tested 202 needs to be in a low temperature state, in order to avoid ice blockage inside the meter to be tested 202, the gas provided by the pressurizing device 3 needs to be dried before testing, and when inflating and pressurizing, it is necessary to ensure that the original air in the meter to be tested 202 has been fully discharged, and then close the air release valve 42 for slow pressurization.

[0039] In the above scheme, refer to the attached Figures 3 to 6 The test box 1 is set on the detection rack 11, and a control detection table 12 is also set on the detection rack 11. The control detection table 12 is used to place the standard meter 201. A fixing fixture 13 is set on the control detection table 12 and in the test box 1. The fixing fixture 13 is used to fix the diaphragm gas meter 2 (the fixture structure is set according to the actual shape of the diaphragm gas meter 2, and no further explanation is given in this embodiment). A docking frame 14 is set on the control detection table 12 and in the test box 1. The docking frame 14 is equipped with a docking pipe 15 that docks with the air inlet pipe 21 and the air outlet pipe 22 respectively. The above-mentioned pipelines are all connected through the docking pipe 15, and the pressurizing device 3 and the remaining devices can be placed in the test box 1, and the docking frame 14 is driven to move by a docking driver 141 (such as a linear drive device such as a cylinder), and is driven to approach or move away from the diaphragm gas meter 2 by the docking driver 141.

[0040] Among them, the docking tube 15 corresponding to the air inlet pipe 21 on the standard meter 201 is connected to the pressurizing device 3 through a pipeline, and the docking tube 15 corresponding to the air outlet pipe 22 of the standard meter 201 is connected to the pipeline corresponding to the air inlet pipe 21 of the meter to be tested 202 through a pipeline, and the air release valve 42 is set on the docking tube 15 corresponding to the air outlet pipe 22 of the meter to be tested 202, thereby completing the above-mentioned pipeline connection. During the inspection, it is only necessary to control the corresponding docking frame 14 to move toward the standard meter 201 or the meter to be tested 202 to realize the docking of each docking tube 15 with the corresponding air inlet pipe 21 and air outlet pipe 22, so as to complete the pipeline connection and perform the above-mentioned inspection.

[0041] Refer to the instruction manual Figure 4 and Figure 5In this embodiment, the standard meter 201 and the meter to be tested 202 can be placed vertically, and in order to facilitate the placement of the standard meter 201 and the meter to be tested 202, the fixing fixture 13 is 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 fixture 13 is driven to move to the deep end, and a box door 101 is provided on the test box 1, and an insulation structure is provided in the box door 101 and the side wall of the test box 1 to ensure the simulation effect of the low temperature environment in the test box 1.

[0042] In this embodiment, the air leakage detection component 6 is an acoustic wave sensing air leakage detection component 61. A sound insulation structure is also provided on the inner wall of the test box 1. The acoustic wave sensing air leakage detection component 61 is arranged in the test box 1 and is used to collect the sound environment in the test box 1. When the temperature in the test box 1 is lowered and there is no leakage in the meter to be tested 202, there is no sound wave generated in the test box 1. When the acoustic wave sensing air leakage detection component 61 recognizes the sound wave, it is determined that a leakage has occurred in the meter to be tested 202 during the cooling process. The acoustic wave sensing air leakage detection component 61 can use multiple groups of acoustic wave sensors evenly distributed in the test box 1, or can use the currently more commonly used acoustic imager (a new type of noise source identification, positioning 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 manage and control noise) to determine whether there is a leakage during the cooling process, but the cost is relatively high.

[0043] By adopting the above scheme, a low-temperature environment can be effectively simulated, and the air tightness of the diaphragm gas meter 2 in a low-temperature environment can be tested, thereby effectively judging the actual quality of the diaphragm gas meter 2, which is beneficial to the continued research and development and design of the diaphragm gas meter 2. Moreover, by temporarily judging the leakage of the meter to be tested 202 with the help of the leakage detection component 6 when the temperature is lowered in the test box 1, the influence of the pressure change caused by the contraction of the gas inside the meter to be tested 202 due to the cooling of the test box 1 on the judgment of whether there is a leak can be eliminated, thereby improving the judgment accuracy of the quality of the diaphragm gas meter 2 and improving the detection quality.

[0044] Embodiment 2. In the above embodiment, the main method of detecting sound waves is to detect whether there is a leak during the cooling process in the test chamber 1, but it is difficult to detect the leakage amount during this process. Therefore, this embodiment provides the following solution. Unlike the above embodiment, the leakage detection component 6 is a gravity-sensing leakage detection component 62. Since the internal air pressure of the meter to be tested 202 is relatively high and the amount of gas is relatively large, when the internal air pressure of the meter to be tested 202 is constant, its relative mass is also relatively stable. Therefore, by judging the relative weight change of the meter to be tested 202 through a highly sensitive pressure sensor, whether there is a leak can be judged, and the leakage amount can also be judged based on the weight change.

[0045] Based on the above principles, refer to the attached manual. Figure 7 This embodiment, based on the detection principle of the first embodiment, makes the following improvements: a pipe separation assembly 17 is provided between the air inlet pipe 21 of the meter under test 202 and the air outlet pipe 22 of the standard meter 201. The pipes on both sides of the pipe separation assembly 17 are respectively provided with a first closed control valve 44 and a second closed control valve 45. A gravity-sensing air leakage detection assembly 62 is provided below the meter under test 202 and is used to weigh the meter under test 202. When the pressure in the pipeline system reaches the required level and the temperature in the test chamber 1 begins to drop, the second closed control valve 45 and the first closed control valve 44 are closed, and the pipe separation assembly 17 is disconnected, so that the meter under test 202 forms a relatively independent unit in the test chamber 1, facilitating weighing by the gravity-sensing air leakage detection assembly 62. After the temperature in the test chamber 1 has completely dropped, the pipe separation assembly 17 can be controlled to be connected again, and the second closed control valve 45 and the first closed control valve 44 can be opened to restore the aforementioned pipe connection, allowing the pressure detection assembly 5 to continue to perform pressure testing on the entire pipeline.

[0046] It should be noted that when the pipeline separation component 17 is re-docking, the overall pressure of the pipeline will be regionally balanced. At this time, the temperature of the meter to be tested 202 will drop and the air pressure will be relatively reduced. Therefore, the pressure value of the external pressure gauge 51 installed outside will drop briefly. If no leakage occurs, the subsequent pressure detection of the external pressure gauge 51 will hardly change. If the subsequent detection value of the external pressure gauge 51 continues to decrease, it is judged that a leakage has occurred. After a period of time after the pipeline separation component 17 is docked, the leakage rate will be judged after the pressure of the meter to be tested 202 and the standard gauge 201 are balanced.

[0047] Specifically, a partition box 16 is provided on the detection rack 11 at the rear position of the test box 1, and the pipe separation assembly 17 and the docking frame 14 are provided in the partition box 16. In this embodiment, the meter to be tested 202 and the docking frame 14 are placed horizontally, and a partition plate 102 is provided between the test box 1 and the partition box 16. The partition plate 102 is provided with an insulation structure inside. The two groups of docking pipes 15 corresponding to the meter to be tested 202 both pass through the partition plate 102, and in order to avoid the partition plate 102 from blocking the docking pipes 15, a gap is provided between the partition plate 102 and the docking pipes 15. A balancing load plate 131 is provided at the bottom of the test box 1 and the partition box 16. The balancing load plate 131 is vertically slidably installed in the detection rack 11. The meter to be tested 202 and the corresponding meter to be tested 202 The docking frame 14 and the docking driver 141 are both installed on the balanced load-bearing plate 131, and the balanced load-bearing plate 131 is connected to the gravity-sensing leakage detection component 62, so that the meter to be tested 202 and its corresponding structure can be placed relatively stably on the same balanced load-bearing plate 131. After the pipeline separation component 17 is separated, the separate system consisting of the meter to be tested 202 and the docking frame 14 can be weighed and tested. If the weight of the system is constant, no leakage occurs during the cooling process. If the weight of the system is reduced, leakage occurs, and the amount of leakage during the cooling process can be calculated based on the weight change. After the cooling is completed, in order to complete the comparative test with the standard meter 201, the pipeline separation component 17 needs to be reconnected to restore the overall detection pipeline.

[0048] Further, in the above scheme, refer to the attached Figure 8 and Figure 9 The air release valve 42 is fixedly mounted on the docking pipe 15 of the air outlet pipe 22 corresponding to the meter to be tested 202, and the first closed control valve 44 is fixedly mounted on the docking pipe 15 corresponding to the air inlet pipe 21 of the meter to be tested 202. The pipeline separation assembly 17 includes a separation pipe 171 and a separation movable seat 172. The separation pipe 171 is arranged corresponding to the docking pipe 15 connected to the air inlet pipe 21. The separation movable seat 172 is slidably mounted in the partition box 16. The separation movable seat 172 is driven to move by a separation driver 173 (such as a linear drive device such as a cylinder). The second closed control valve 45 is mounted on the separation pipe 171, and then by driving the separation pipe 171 to move and dock or separate with the docking pipe 15, the separation and re-docking of the pipeline separation assembly 17 can be achieved.

[0049] The gravity-sensing air leakage detection assembly 62 includes a weighing plate 621, and a weighing sensor 622 is provided at the bottom of the weighing plate 621. The balancing load plate 131 is fixedly connected to the weighing plate 621 through a connecting structure, and the overall weight of the balancing load plate 131 is then judged by the weighing sensor 622. The weighing sensor 622 is preferably a highly sensitive pressure sensor (such as a capacitive pressure sensor or a Hall element pressure sensor, etc.), which converts gravity into pressure on the sensor to perform weight detection.

[0050] Furthermore, since the density of the gas is relatively low, the weight change is relatively small. In order to facilitate detection and make a more effective judgment on the change, a corresponding balance structure can be set up. For example, refer to the attached manual. Figure 10 and Figure 12 A weighing rod 623 is rotatably mounted on the detection frame 11, and an inverted frame 624 is also fixedly mounted on the detection frame 11. The weighing sensor 622 is mounted on the inverted frame 624, and the detection end of the weighing sensor 622 is set downward. The long arm end of the weighing rod 623 contacts the bottom of the weighing plate 621, and the short arm end of the weighing rod 623 contacts the detection end of the weighing sensor 622, and then a lever is formed with the help of the weighing rod 623 to amplify the pressure of the weighing plate 621 and transmit it to the weighing sensor 622, so that the weight change on the balanced load-bearing plate 131 can be judged more accurately. In addition, a built-in pressure gauge 52 is also provided on the docking pipe 15 of the air intake pipe 21 corresponding to the meter to be tested 202, which is used to separately detect the internal pressure value of the meter to be tested 202 when the pipeline separation component 17 is disconnected, so as to facilitate subsequent comparison and judgment.

[0051] In addition to using load cell 622 to amplify force, it is also possible to measure the amount of gas in the entire pipeline, such as butane or propane, or a mixture thereof. These gases are gaseous at room temperature and pressure, but can become liquid under pressure (refer to the fuel inside a lighter). When a leak occurs, the amount of liquid in the meter under test 202 decreases, and the leaked material returns to gas due to the reduced pressure and does not remain on the meter under test 202, making it easier to determine the weight of the meter under test 202.

[0052] Furthermore, since the air contains moisture, it is easy to freeze in the low temperature environment of the test box 1 and affect the weighing effect of the gravity-sensing air leakage detection component 62. Therefore, it is necessary to dry the air in the test box 1, for example, refer to the attached manual. Figure 10 and Figure 11The test box 1 is provided with a cold air intake pipe 103, which is connected to a low-temperature air source 18. The partition box 16 is provided with an exhaust pipe 161 and a hot air intake pipe 162. The hot air intake pipe 162 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 in the test box 1 is constant, it is input into the test box 1, and the air is dried to ensure that the air in the test box 1 is always dry. The high-temperature air source 19 includes a second air pump 181 and an air cooler 182. Pump 191 and air heater 192, the air heater 192 is used to heat the air, wherein, in order to avoid affecting the weighing of the gravity-sensing air leakage detection component 62, a movable gap is left between the partition plate 102 and the docking pipe 15 and other corresponding structures, and the excess air in the test box 1 flows from the gap to the partition box 16 and is discharged from the exhaust pipe 161. In order to avoid the corresponding valves and meters in the partition box 16 from being affected by low temperature, high-temperature air is input into the partition box 16 with the help of a high-temperature air source 19 to neutralize the low-temperature air.

[0053] It should be noted that for the related equipment on the balancing carrier plate 131 that needs power supply and control, battery power supply, wireless control and wireless signal transmission are preferred, or soft connecting wires are used, or line docking devices are added to control the docking or separation of the connecting wires when necessary.

[0054] The above-described embodiments merely illustrate several implementations of the present invention. 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 a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A gas meter air tightness detection device, characterized by: The test chamber (1) comprises a test chamber (1), a standard meter (201), a meter to be tested (202), a pressurizing device (3), a valve assembly (4) and a pressure detection assembly (5), wherein the valve assembly (4) comprises a pressure regulating valve (41), an air release valve (42) and a drain valve (43), and a cooling device is provided in the test chamber (1); 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 box (1), and the air release valve (42) is provided on the connecting pipe of the air outlet pipe (22) of the meter to be tested (202); The test box (1) is further provided with a gas leakage detection component (6), which is used to detect whether there is gas leakage in the meter to be tested (202) when the test box (1) is gradually cooled down inside the test box (1).

2. A gas meter air tightness detection device according to claim 1, characterized in that: The test box (1) is arranged on a test frame (11), and a control test table (12) is further arranged on the test frame (11), and the control test table (12) is used to place a standard meter (201). A fixing fixture (13) is provided on the control test table (12) and in the test box (1), and the fixing fixture (13) is used to fix the membrane gas meter (2). A docking frame (14) is provided on the control test table (12) and in the test box (1), and a docking pipe (15) is installed on the docking frame (14) for docking with the air inlet pipe (21) and the air outlet pipe (22) respectively. The docking frame (14) is driven to move by a docking driver (141).

3. A gas meter air tightness detection device according to claim 2, characterized in that: The fixing fixtures (13) are 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 fixtures (13) are driven to move to a deep position, and a box door (101) is provided on the test box (1), and a heat insulation structure is provided in the box door (101) and the side wall of the test box (1).

4. A gas meter air tightness detection device according to claim 3, characterized in that: The air leakage detection component (6) is an acoustic wave induction type air leakage detection component (61), and a sound insulation structure is further provided on the inner wall of the test box (1). The acoustic wave induction type air leakage detection component (61) is arranged in the test box (1). The acoustic wave induction type air leakage detection component (61) includes a plurality of groups of acoustic wave sensors and acoustic imagers evenly distributed in the test box (1), and the acoustic imager is installed on the box door (101).

5. A gas meter air tightness detection device according to claim 3, characterized in that: A pipeline separation component (17) is provided between the air inlet pipe (21) of the meter to be tested (202) and the air outlet pipe (22) of the standard meter (201), and pipelines on both sides of the pipeline separation component (17) are respectively provided with a first closed control valve (44) and a second closed control valve (45).

6. A gas meter air tightness detection device according to claim 5, characterized in that: A partition box (16) is provided on the detection rack (11) at the rear of the test box (1), the pipe separation assembly (17) and the docking frame (14) are provided in the partition box (16), the meter to be tested (202) and the docking frame (14) are placed horizontally, a partition board (102) is provided between the test box (1) and the partition box (16), and a heat-insulating structure is provided inside the partition board (102), corresponding to the two sets of docking pipes (15) of the meter to be tested (202) Both penetrate the partition plate (102), a gap is provided between the partition plate (102) and the docking pipe (15), a balancing load-bearing plate (131) is provided at the bottom of the test box (1) and the partition box (16), the balancing load-bearing plate (131) is vertically slidably mounted in the detection rack (11), and the meter to be tested (202) and the docking rack (14) and the docking driver (141) corresponding to the meter to be tested (202) are all mounted on the balancing load-bearing plate (131).

7. A gas meter air tightness detection device according to claim 6, characterized in that: The air leakage detection assembly (6) is a gravity-sensing air leakage detection assembly (62), and the gravity-sensing air leakage detection assembly (62) includes a weighing plate (621). The balancing load-bearing plate (131) is fixedly connected to the weighing plate (621) via a connecting structure, and the weighing plate (621) is connected to a weighing sensor (622).

8. A gas meter air tightness detection device according to claim 7, characterized in that: A weighing beam (623) is rotatably mounted on the detection frame (11), and an inverted frame (624) is fixedly mounted on the detection frame (11). The weighing sensor (622) is mounted on the inverted frame (624), and the detection end of the weighing sensor (622) is arranged downward, the long arm end of the weighing beam (623) contacts the bottom of the weighing plate (621), and the short wall end of the weighing beam (623) contacts the detection end of the weighing sensor (622).

9. A gas meter air tightness detection device according to claim 8, characterized in that: The pressure regulating valve (41) is arranged on the pipeline between the pressurizing device (3) and the standard gauge (201), the drain valve (43) is arranged 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 assembly (5) includes an external pressure gauge (51) and a built-in pressure gauge (52), the external pressure gauge (51) is arranged on the pipeline outside the test box (1), and the built-in pressure gauge (52) is arranged on the butt joint pipe (15) corresponding to the inlet pipe (21) of the gauge to be tested (202).

10. A gas meter air tightness detection device according to claim 9, characterized in that: The test box (1) is provided with a cold air intake pipe (103), and the cold air intake pipe (103) is connected to a low-temperature air source (18). The partition box (16) is provided with an exhaust pipe (161) and a hot air intake pipe (162), and the hot air intake pipe (162) 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), and the high-temperature air source (19) includes a second air pump (191) and an air heater (192).

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