A gas flow standard device with a sealed test station

Abstract

This utility model discloses a gas flow standard device with a sealing test station, belonging to the technical field of gas flow standard devices. It includes a first sealing test station; the first sealing test station comprises an upstream straight pipe section and a downstream straight pipe section, with a test device mounting section between the upstream and downstream straight pipe sections; the inlet end of the upstream straight pipe section includes a first inlet end and a second inlet end, with an upstream shut-off valve at the first inlet end and a downstream shut-off valve at the outlet end of the downstream straight pipe section; an air compressor is connected to the second inlet end of the upstream straight pipe. This utility model improves upon traditional negative pressure gas flow standard devices by adding a sealing test function, eliminating the need for specialized equipment construction, and can meet the calibration requirements of various flow meters.

Description

Technical Field

[0001] This utility model relates to the technical field of gas flow standard devices, specifically a gas flow standard device with a sealed test station. Background Technology

[0002] Steam and natural gas, as gaseous energy sources, are important components of my country's energy supply industry, playing a vital role in energy consumption in both industrial production and residential use. Consequently, a large and widespread market demand for trade metering has emerged. Among these, various types of gas flow meters, as an indispensable part of energy metering, are working measuring instruments within the scope of mandatory verification.

[0003] When verifying working measuring instruments, it is necessary to follow the relevant national verification procedures. The most important verification item is the evaluation of the metrological performance of the tested instrument. This is done by using a flow standard device to conduct indication error and repeatability tests on the flowmeter under test to determine whether it meets the specification requirements. In addition, the verification procedures also have a clear evaluation system for the general technical indicators of flowmeters. For some working measuring instruments, such as ultrasonic, turbine, and volumetric flowmeters, the inspection items also include the criteria for judging the sealing ability. The sealing test requires the tested instrument to remain leak-free for a period of time under specific pressure conditions. The specific pressure value depends on the nameplate information of the tested instrument and is usually slightly higher than the maximum working pressure. In this case, the test device is required to provide an adjustable positive pressure test condition.

[0004] For most traditional gas flow standard devices, considering economy and universality, a negative pressure system is generally adopted, with a vacuum pump as the power source. By adjusting and controlling the vacuum degree of the pressure stabilizing container, the pressure difference formed between the atmospheric pressure and the negative pressure inside the container is used to achieve the required flow rate for the test. Since such devices can only provide negative pressure working conditions, they cannot conduct sealing tests on the tested device.

[0005] As a positive pressure device, the bell-type gas flow device has many advantages, but due to its mechanical structure and working principle, it is generally only suitable for calibrating the test device with a small flow range. Moreover, its working pressure is low, so it cannot meet the requirements of the sealing test.

[0006] Flow standard devices based on steam gate stations or national natural gas pipelines are subject to numerous stringent safety regulations and procedures during testing due to requirements such as high temperature, high pressure, leakage prevention, and explosion prevention. Although they can meet the requirements for sealing tests, there are very few such devices, and their operating costs are too high. The installation and commissioning time required before each test is also very long. Therefore, their ability to provide metrological verification services to the market is very limited.

[0007] For other positive pressure system gas flow devices, it is necessary to achieve necessary measures such as maintaining pressure under high flow conditions, controlling the instability of medium temperature caused by the heating of the control system, or controlling the humidity of the medium after water bath temperature control. This makes the construction and operation costs of the device very high. As a result, the development of such devices is still in the exploration and trial production stage, and there are no mature cases of market operation.

[0008] Currently, when calibrating ultrasonic, turbine, and volumetric gas flow meters, it is generally necessary to conduct indication error tests on the flow device and sealing tests on dedicated pressurization equipment. Not only does the construction of the equipment occupy a large amount of laboratory space, but the loading and unloading of the device under test between different devices also consumes a lot of time and costs, resulting in low efficiency of calibration tests. Utility Model Content

[0009] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a gas flow standard device with a sealing test station, including an air compressor, a first sealing test station, a standard flow meter, a pressure stabilizing container, a vacuum pump, and a PLC control module;

[0010] The first station of the sealing test includes an upstream straight pipe section and a downstream straight pipe section. A test device installation section is provided between the outlet end of the upstream straight pipe section and the inlet end of the downstream straight pipe section. The test device installation section is used to place the flow meter under test.

[0011] The air inlet of the upstream straight pipe section of the first workstation includes a first air inlet and a second air inlet of the upstream straight pipe. A first upstream shut-off valve is provided at the first air inlet of the upstream straight pipe, and a first downstream shut-off valve is provided at the outlet of the downstream straight pipe section of the first workstation. The output of the air compressor is connected to the second air inlet of the upstream straight pipe of the first workstation through a first three-position three-way valve. A first relay is provided on the first three-position three-way valve. A first workstation pressure regulator is provided on the air pipeline between the output of the air compressor and the first three-position three-way valve. A first workstation pressure sensor is provided on the air pipeline between the first three-position three-way valve and the second air inlet of the upstream straight pipe of the first workstation. A first workstation temperature and humidity sensor is provided on the downstream straight pipe section of the first workstation.

[0012] The outlet end of the downstream straight pipe section of the first workstation, the standard flow meter, the pressure stabilizing container, and the vacuum pump are connected in sequence through an air pipeline;

[0013] The first station pressure regulator, the first station upstream shut-off valve, the first relay, the first station pressure sensor, and the first station downstream shut-off valve are all electrically connected to the PLC control module, and the PLC control module is electrically connected to the vacuum pump through a frequency converter.

[0014] Furthermore, it also includes a first station telescopic thruster, which is equipped with a first station thrust direction controller. The first station thrust direction controller is electrically connected to the PLC control module. The output end of the first station telescopic thruster is connected to the end of the upstream straight pipe section of the first station away from the downstream straight pipe section of the first station, and is used to drive the upstream straight pipe section of the first station to clamp the flow meter under test located in the test device installation section of the first station.

[0015] Furthermore, in the first station of the sealing test, the diameter of the air pipe is D1, the length of the upstream straight pipe section of the first station is ≥10D1, and the length of the downstream straight pipe section of the first station is ≥5D1.

[0016] Furthermore, it also includes a second station for sealing testing;

[0017] The second station of the sealing test includes an upstream straight pipe section and a downstream straight pipe section. A test device mounting section is provided between the outlet end of the upstream straight pipe section and the inlet end of the downstream straight pipe section. The test device mounting section is used to place the flow meter under test.

[0018] The air inlet of the upstream straight pipe section of the second station includes a first air inlet and a second air inlet of the upstream straight pipe of the second station. A second station upstream shut-off valve is provided at the first air inlet of the upstream straight pipe of the second station, and a second station downstream shut-off valve is provided at the outlet of the downstream straight pipe section of the second station. The output of the air compressor is connected to the second air inlet of the upstream straight pipe of the second station through a second three-position three-way valve. A second relay is provided on the second three-position three-way valve. A second station pressure regulator is provided on the air pipeline between the output of the air compressor and the second three-position three-way valve. A second station pressure sensor is provided on the air pipeline between the second three-position three-way valve and the second air inlet of the upstream straight pipe of the second station. A second station temperature and humidity sensor is provided on the downstream straight pipe section of the second station.

[0019] The outlet end of the downstream straight pipe section of the second workstation, the standard flow meter, the pressure stabilizing container, and the vacuum pump are connected in sequence through an air pipeline;

[0020] The second station pressure regulator, the second station upstream shut-off valve, the second relay, the second station pressure sensor, and the second station downstream shut-off valve are all electrically connected to the PLC control module.

[0021] Furthermore, it also includes a second station telescopic thruster, which is equipped with a second station thrust direction controller. The second station thrust direction controller is electrically connected to the PLC control module. The output end of the second station telescopic thruster is connected to the end of the upstream straight pipe section of the second station away from the downstream straight pipe section of the second station, and is used to drive the upstream straight pipe section of the second station to clamp the flow meter under test located in the installation section of the device under test in the second station.

[0022] Furthermore, in the second station of the sealing test, the diameter of the air pipe is D2, the length of the upstream straight pipe section of the second station is ≥10D2, and the length of the downstream straight pipe section of the second station is ≥5D2.

[0023] Furthermore, the PLC control module is electrically connected to an operating computer.

[0024] The beneficial effects of this utility model are as follows:

[0025] 1. This utility model improves the structure of the traditional negative pressure gas flow standard device, adds a sealing test function, eliminates the need to build special equipment, and can more conveniently and comprehensively meet the calibration needs of various flow meters.

[0026] 2. By setting up two relatively independent workstations, this utility model can alternately carry out sealing tests and flow indication error tests without affecting each other, which can effectively improve the efficiency of the verification work. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a gas flow standard device with a sealed test station according to the present invention.

[0029] In the figure:

[0030] 1. Air compressor; 2a. Telescopic thruster at the first station; 2b. Telescopic thruster at the second station; 3a. Thrust direction controller at the first station; 3b. Thrust direction controller at the second station; 4a. Upstream shut-off valve at the first station; 4b. Upstream shut-off valve at the second station; 5a. Upstream straight pipe section at the first station; 5b. Upstream straight pipe section at the second station; 6a. Pressure sensor at the first station; 6b. Pressure sensor at the second station; 7a. Mounting section for the inspected device at the first station; 7b. Mounting section for the inspected device at the second station; 8a. Downstream straight pipe section at the first station; 8b. Downstream straight pipe section of two stations; 9a. Temperature and humidity sensor of the first station; 9b. Temperature and humidity sensor of the second station; 10a. Downstream shut-off valve of the first station; 10b. Downstream shut-off valve of the second station; 11a. Pressure regulator of the first station; 11b. Pressure regulator of the second station; 12a. First relay; 12b. Second relay; 13a. First three-position three-way valve; 13b. Second three-position three-way valve; 14. PLC control module; 15. Operating computer; 16. Standard flow meter; 17. Pressure stabilizing vessel; 18. Frequency converter; 19. Vacuum pump. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] See appendix Figure 1 This utility model discloses a gas flow standard device with a sealing test station, including an air compressor 1, a first sealing test station, a standard flow meter 16, a pressure stabilizing container 17, a vacuum pump 19, and a PLC control module 14.

[0033] The first station of the sealing test includes an upstream straight pipe section 5a and a downstream straight pipe section 8a. A test device installation section 7a is provided between the outlet end of the upstream straight pipe section 5a and the inlet end of the downstream straight pipe section 8a. The test device installation section 7a is used to place the flow meter under test.

[0034] The air inlet of the upstream straight pipe section 5a of the first station includes the first air inlet of the upstream straight pipe and the second air inlet of the upstream straight pipe. The first air inlet of the upstream straight pipe is equipped with the first station upstream shut-off valve 4a. The air outlet of the downstream straight pipe section 8a of the first station is equipped with the first station downstream shut-off valve 10a. The output of the air compressor 1 is connected to the second air inlet of the upstream straight pipe through the first three-position three-way valve 13a. The first three-position three-way valve 13a is equipped with the first relay 12a. The air pipeline between the output of the air compressor 1 and the first three-position three-way valve 13a is equipped with the first station pressure regulator 11a. The air pipeline between the first three-position three-way valve 13a and the second air inlet of the upstream straight pipe is equipped with the first station pressure sensor 6a. The downstream straight pipe section 8a of the first station is equipped with the first station temperature and humidity sensor 9a.

[0035] The outlet end of the downstream straight pipe section 8a of the first station, the standard flow meter 16, the pressure stabilizing container 17 and the vacuum pump 19 are connected in sequence through an air pipeline.

[0036] The first station pressure regulator 11a, the first station upstream shut-off valve 4a, the first relay 12a, the first station pressure sensor 6a, and the first station downstream shut-off valve 10a are all electrically connected to the PLC control module 14. The PLC control module 14 is electrically connected to the vacuum pump 19 through the frequency converter 18.

[0037] In this embodiment, the standard flow meter 16 can also be a critical flow nozzle assembly or other forms of standard meter.

[0038] A gas flow standard device with a sealed test station also includes a first station telescopic thruster 2a. The first station telescopic thruster 2a is equipped with a first station thrust direction controller 3a. The first station thrust direction controller 3a is electrically connected to a PLC control module 14. The output end of the first station telescopic thruster 2a is connected to the end of the upstream straight pipe section 5a of the first station away from the downstream straight pipe section 8a of the first station, and is used to drive the upstream straight pipe section 5a of the first station to clamp the flow meter under test located in the test device installation section 7a of the first station.

[0039] In the first station of the sealing test, the diameter of the air pipeline is D1, the length of the upstream straight pipe section 5a of the first station is ≥10D1, and the length of the downstream straight pipe section 8a of the first station is ≥5D1.

[0040] A gas flow standard device with a sealing test station also includes a second sealing test station;

[0041] The second station of the sealing test includes an upstream straight pipe section 5b and a downstream straight pipe section 8b. The test device installation section 7b is provided between the outlet end of the upstream straight pipe section 5b and the inlet end of the downstream straight pipe section 8b. The test device installation section 7b is used to place the flow meter under test.

[0042] The air inlet of the upstream straight pipe section 5b of the second station includes the first air inlet of the upstream straight pipe of the second station and the second air inlet of the upstream straight pipe of the second station. The first air inlet of the upstream straight pipe of the second station is equipped with the upstream shut-off valve 4b of the second station. The outlet of the downstream straight pipe section 8b of the second station is equipped with the downstream shut-off valve 10b of the second station. The output of the air compressor 1 is connected to the second air inlet of the upstream straight pipe of the second station through the second three-position three-way valve 13b. The second three-position three-way valve 13b is equipped with the second relay 12b. The air pipeline between the output of the air compressor 1 and the second three-position three-way valve 13b is equipped with the second station pressure regulator 11b. The air pipeline between the second three-position three-way valve 13b and the second air inlet of the upstream straight pipe of the second station is equipped with the second station pressure sensor 6b. The downstream straight pipe section 8b of the second station is equipped with the second station temperature and humidity sensor 9b.

[0043] The outlet of the downstream straight pipe section 8b of the second station, the standard flow meter 16, the pressure stabilizing container 17 and the vacuum pump 19 are connected in sequence through an air pipeline.

[0044] The second station pressure regulator 11b, the second station upstream shut-off valve 4b, the second relay 12b, the second station pressure sensor 6b, and the second station downstream shut-off valve 10b are all electrically connected to the PLC control module 14.

[0045] A gas flow standard device with a sealing test station also includes a second station telescopic thruster 2b. The second station telescopic thruster 2b is equipped with a second station thrust direction controller 3b, which is electrically connected to a PLC control module 14. The output end of the second station telescopic thruster 2b is connected to the end of the upstream straight pipe section 5b of the second station away from the downstream straight pipe section 8b of the second station, and is used to drive the upstream straight pipe section 5b of the second station to clamp the flow meter under test located in the test device mounting section 7b of the second station.

[0046] In the second station of the sealing test, the diameter of the air pipeline is D2, the length of the upstream straight pipe section 5b of the second station is ≥10D2, and the length of the downstream straight pipe section 8b of the second station is ≥5D2.

[0047] The PLC control module 14 is electrically connected to the operating computer 15.

[0048] In this embodiment, the first and second stations of the sealing test can be designed with air pipelines of different inner diameters as required.

[0049] Sealing test procedure:

[0050] Taking the first station of the sealing test as an example, the flow meter under test is placed in the test device installation section 7a of the first station. After adjusting it to be coaxially aligned with the upstream straight pipe section 5a and the downstream straight pipe section 8a of the first station, the thruster of the telescopic thruster of the first station is controlled to drive the upstream straight pipe section 5a of the first station to clamp the flow meter under test.

[0051] At this time, the upstream shut-off valve 4a and the downstream shut-off valve 10a of the first station are closed to seal the working chamber where the flow meter under test is located. The pressure regulator 11a of the first station is adjusted according to the pressure required for the test to supply pressure. The passage of the first three-position three-way valve 13a is controlled by the first relay 12a.

[0052] At the start of the test, the first three-way valve 13a is switched to the left position I to pressurize the second air inlet of the first straight pipe section 5a upstream of the first station. After the pressure sensor 6a of the first station detects that the pressure is stable, it provides feedback. At this time, the first three-way valve 13a is switched to the middle position II to lock the air path. The initial pressure value is recorded. The test time is set according to the test requirements, and the end pressure value is recorded after the time is over. The sealing performance of the flow meter under test is evaluated by the pressure difference between the two values. After the test is completed, the first three-way valve 13a is switched to the right position III to depressurize. The control of each valve, relay and sensor signal reception is completed through the PLC control module 14 and the operating computer 15.

[0053] Procedure for testing flow rate indication error:

[0054] Taking the first station of the sealing test as an example, after the sealing test is completed and the pressure is released, the upstream shut-off valve 4a and the downstream shut-off valve 10a of the first station are opened, the first three-position three-way valve 13a is switched to the middle position II, the second air inlet of the upstream straight pipe section 5a of the first station is locked, and the upstream shut-off valve 4b and the downstream shut-off valve 10b of the second station are closed, so that the air path of the flow device only passes through a single flow meter under test.

[0055] The complete path is: Atmosphere — upstream straight pipe section 5a of the first station — flow meter under test — downstream straight pipe section 8a of the first station — standard flow meter 16 — pressure stabilizing vessel 17 — vacuum pump 19 — Atmosphere.

[0056] The operating speed of the vacuum pump 19 is controlled by the frequency converter 18, the required flow rate is adjusted, the flow rate reading of the standard flow meter 16 is read, the air state parameters at the flow meter under test are measured by the first station pressure sensor 6a and the first station temperature and humidity sensor 9a, and the flow rate reading of the standard flow meter 16 is converted to the flow rate at that location as the standard value, and the indication error of the flow meter under test is calculated.

[0057] This invention enables non-interfering testing by controlling the independent closure of different workstations or their independent connection with the standard flow meter 16, pressure stabilizing container 17, vacuum pump 19, and atmospheric environment. For example, while the first workstation performs a sealing test on one flow meter under test, the second workstation performs a flow indication error test on another flow meter under test. After completing the corresponding tests, the two workstations switch their operating modes to switch the test items.

[0058] This invention has a certain degree of scalability and can be expanded to include more workstations with different pipe inner diameters according to actual needs.

[0059] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A gas flow rate standard device with a sealed test station, characterized in that, It includes an air compressor (1), a first station for sealing test, a standard flow meter (16), a pressure stabilizing vessel (17), a vacuum pump (19), and a PLC control module (14); The first station of the sealing test includes an upstream straight pipe section (5a) and a downstream straight pipe section (8a). A test device mounting section (7a) is provided between the outlet end of the upstream straight pipe section (5a) and the inlet end of the downstream straight pipe section (8a). The test device mounting section (7a) is used to place the flow meter under test. The air inlet of the upstream straight pipe section (5a) of the first work station includes the first air inlet of the upstream straight pipe and the second air inlet of the upstream straight pipe. The first air inlet of the upstream straight pipe is provided with a first upstream shut-off valve (4a). The outlet of the downstream straight pipe section (8a) of the first work station is provided with a first downstream shut-off valve (10a). The output of the air compressor (1) is connected to the second air inlet of the upstream straight pipe of the first work station through a first three-position three-way valve (13a). The first three-position three-way valve (13a) is provided with a first relay (12a). The air pipeline between the output of the air compressor (1) and the first three-position three-way valve (13a) is provided with a first work station pressure regulator (11a). The air pipeline between the first three-position three-way valve (13a) and the second air inlet of the upstream straight pipe of the first work station is provided with a first work station pressure sensor (6a). The downstream straight pipe section (8a) of the first work station is provided with a first work station temperature and humidity sensor (9a). The outlet of the downstream straight pipe section (8a) of the first work station, the standard flow meter (16), the pressure stabilizing container (17) and the vacuum pump (19) are connected in sequence through an air pipeline; The first station pressure regulator (11a), the first station upstream shut-off valve (4a), the first relay (12a), the first station pressure sensor (6a), and the first station downstream shut-off valve (10a) are all electrically connected to the PLC control module (14), and the PLC control module (14) is electrically connected to the vacuum pump (19) through the frequency converter (18).

2. The gas flow standard device with a sealing test station according to claim 1, characterized in that, It also includes a first station telescopic thruster (2a), on which a first station thrust direction controller (3a) is provided. The first station thrust direction controller (3a) is electrically connected to the PLC control module (14). The output end of the first station telescopic thruster (2a) is connected to the end of the upstream straight pipe section (5a) of the first station away from the downstream straight pipe section (8a) of the first station, and is used to drive the upstream straight pipe section (5a) of the first station to clamp the flow meter under test located in the test device installation section (7a) of the first station.

3. A gas flow standard device with a sealing test station according to claim 1 or 2, characterized in that, The diameter of the air pipe in the first station of the sealing test is D1, the length of the upstream straight pipe section (5a) of the first station is ≥10D1, and the length of the downstream straight pipe section (8a) of the first station is ≥5D1.

4. A gas flow standard device with a sealing test station according to claim 1, characterized in that, It also includes a second station for sealing testing; The second station of the sealing test includes an upstream straight pipe section (5b) and a downstream straight pipe section (8b). A test device mounting section (7b) is provided between the outlet end of the upstream straight pipe section (5b) and the inlet end of the downstream straight pipe section (8b). The test device mounting section (7b) is used to place the flow meter under test. The air inlet of the upstream straight pipe section (5b) of the second station includes the first air inlet of the upstream straight pipe of the second station and the second air inlet of the upstream straight pipe of the second station. The first air inlet of the upstream straight pipe of the second station is provided with a second station upstream shut-off valve (4b). The outlet of the downstream straight pipe section (8b) of the second station is provided with a second station downstream shut-off valve (10b). The output of the air compressor (1) is connected to the second air inlet of the upstream straight pipe of the second station through a second three-position three-way valve (13b). The second three-position three-way valve (13b) is provided with a second relay (12b). The air pipeline between the output of the air compressor (1) and the second three-position three-way valve (13b) is provided with a second station pressure regulator (11b). The air pipeline between the second three-position three-way valve (13b) and the second air inlet of the upstream straight pipe of the second station is provided with a second station pressure sensor (6b). The downstream straight pipe section (8b) of the second station is provided with a second station temperature and humidity sensor (9b). The outlet of the downstream straight pipe section (8b) of the second work station, the standard flow meter (16), the pressure stabilizing container (17) and the vacuum pump (19) are connected in sequence through an air pipeline; The second station pressure regulator (11b), the second station upstream shut-off valve (4b), the second relay (12b), the second station pressure sensor (6b), and the second station downstream shut-off valve (10b) are all electrically connected to the PLC control module (14).

5. A gas flow standard device with a sealing test station according to claim 4, characterized in that, It also includes a second station telescopic thruster (2b), on which a second station thrust direction controller (3b) is provided. The second station thrust direction controller (3b) is electrically connected to the PLC control module (14). The output end of the second station telescopic thruster (2b) is connected to the end of the upstream straight pipe section (5b) of the second station away from the downstream straight pipe section (8b) of the second station, and is used to drive the upstream straight pipe section (5b) of the second station to clamp the flow meter under test located in the test device installation section (7b) of the second station.

6. A gas flow standard device with a sealing test station according to claim 4 or 5, characterized in that, The diameter of the air pipe in the second station of the sealing test is D2, the length of the upstream straight pipe section (5b) of the second station is ≥10D2, and the length of the downstream straight pipe section (8b) of the second station is ≥5D2.

7. A gas flow standard device with a sealing test station according to claim 1, characterized in that, The PLC control module (14) is electrically connected to the operating computer (15).

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