Performance test method of vacuum pump

Abstract

The invention belongs to the technical field of vacuum pump performance testing, and discloses a vacuum pump performance testing method which comprises the following steps: step (1), a buffer tank is communicated with the atmosphere through a single air inlet pipeline, and a to-be-tested vacuum pump operates at a preset rotating speed to extract air in the buffer tank, the air inlet pipeline controls the pressure in the buffer tank through the opening degree of the valve; (2) pressure data of a pressure meter and volume flow data of an orifice plate type flowmeter of the air inlet pipeline are collected respectively, and a vacuum pump performance curve graph under the current working condition is constructed through the pressure data and the volume flow data; (3) when the data of the pore plate type flow meter of the air inlet pipeline is invalid data, closing the air inlet pipeline and switching to the next air inlet pipeline, and then carrying out the steps (1)-(3) again until the test of all the air inlet pipelines is completed; and the pipe diameter of the next air inlet pipeline is smaller than that of the previous air inlet pipeline. The method can accurately test the performance of the vacuum pump.

Description

Technical Field

[0001] This application belongs to the field of vacuum pump performance testing technology, and more specifically, relates to a method for testing the performance of a vacuum pump. Background Technology

[0002] Vacuum pumps, as a core fluid machinery, reduce gas pressure and create a vacuum environment in enclosed spaces through specific working principles. They are widely used in many key fields such as semiconductor manufacturing, photovoltaic industry, biomedicine, aerospace, vacuum coating, food processing, and chemicals. In the photolithography and etching processes of semiconductor chip manufacturing, ultra-high vacuum environments are required to ensure process precision and product yield. In the freeze-drying and aseptic packaging processes of vaccines in the biomedical field, stable vacuum conditions are relied upon to achieve microbial control and product quality preservation. In the aerospace field, satellite component testing and engine simulation experiments place stringent requirements on the ultimate vacuum level and operational stability of vacuum pumps. With the technological upgrading of downstream industries, vacuum pumps are developing towards higher vacuum levels, higher pumping speeds, lower energy consumption, miniaturization, and intelligence. Their technical performance directly affects the quality of end products, production efficiency, and equipment operational safety.

[0003] Against this backdrop, performance testing of vacuum pumps before they leave the factory has become a crucial step in ensuring product quality. Because the performance of a vacuum pump is affected by multiple factors, including structural design, component precision, assembly processes, and material properties, even products from the same batch may experience performance fluctuations due to minor differences during the production process. From an industry perspective, several vacuum pump performance testing standards have been issued in China. Therefore, to meet the requirements of the national standard GB / T 40344.1-2021, this applicant proposes a vacuum pump performance testing method that accurately adapts to the requirements of this standard and is applicable to various types of vacuum pumps. Summary of the Invention

[0004] The main objective of this application is to provide a performance testing method for vacuum pumps, which can accurately test the performance of vacuum pumps.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A performance testing method for a vacuum pump is disclosed. This method involves a testing platform comprising multiple inlet pipes, the diameter of which decreases sequentially. One end of each inlet pipe is an inlet, and the other end is connected to the vacuum pump under test via a common buffer tank. Valves and orifice plate flow meters are installed on each inlet pipe. The measurement range of the orifice plate flow meters decreases as the diameter of the inlet pipe decreases. A pressure gauge is installed on the buffer tank. The method includes the following steps:

[0007] Step (1): The buffer tank is connected to the atmosphere through a single air intake pipe. The vacuum pump to be tested operates at a preset speed to extract air from the buffer tank. The pressure inside the buffer tank is controlled by the opening of the valve in the air intake pipe.

[0008] Step (2): Collect the pressure data from the pressure gauge and the volumetric flow rate data from the orifice plate flow meter of the inlet pipe respectively, and construct the vacuum pump performance curve under the current working condition using the pressure data and volumetric flow rate data.

[0009] Step (3): When the data of the orifice plate flow meter of the air inlet pipe is invalid, close the air inlet pipe and switch to the next air inlet pipe at the same time, and repeat steps 1 to 3 until all air inlet pipes are tested; wherein, the diameter of the next air inlet pipe is smaller than the diameter of the previous air inlet pipe.

[0010] In the above-mentioned vacuum pump performance test method, in step (1), if the inlet pipe used is the inlet pipe with the smallest diameter, then when the data of the orifice plate flow meter of the inlet pipe is invalid, the inlet pipe is closed and the test is stopped.

[0011] In the above-mentioned vacuum pump performance testing method, in step (2), there are six inlet pipes, namely the first inlet pipe, the second inlet pipe, the third inlet pipe, the fourth inlet pipe, the fifth inlet pipe and the sixth inlet pipe, and the pipe diameters of the first inlet pipe, the second inlet pipe, the third inlet pipe, the fourth inlet pipe, the fifth inlet pipe and the sixth inlet pipe decrease sequentially; there are five orifice plate flow meters, namely the first orifice plate flow meter, the second orifice plate flow meter, the third orifice plate flow meter, the fourth orifice plate flow meter, the fifth orifice plate flow meter and the sixth orifice plate flow meter, and the measurement ranges of the first orifice plate flow meter, the second orifice plate flow meter, the third orifice plate flow meter, the fourth orifice plate flow meter, the fifth orifice plate flow meter and the sixth orifice plate flow meter decrease sequentially and their endpoints coincide; the number of valves matches the number of inlet pipes;

[0012] In step (3), the switching method is based on the pipe diameter of the first intake pipe, the second intake pipe, the third intake pipe, the fourth intake pipe, the fifth intake pipe and the sixth intake pipe.

[0013] In the aforementioned vacuum pump performance testing method, the measurement range of the first orifice plate flow meter is 5200 m³ / h to 1300 m³ / h; the measurement range of the second orifice plate flow meter is 2800 m³ / h to 700 m³ / h; the measurement range of the third orifice plate flow meter is 1800 m³ / h to 450 m³ / h; the measurement range of the fourth orifice plate flow meter is 800 m³ / h to 300 m³ / h; the measurement range of the fifth orifice plate flow meter is 460 m³ / h to 92 m³ / h; and the measurement range of the sixth orifice plate flow meter is 100 m³ / h to 20 m³ / h.

[0014] The specific steps (3) are as follows: when the data of the orifice plate flow meter of the air inlet pipe is invalid, record the current pressure data, then close the air inlet pipe and switch to the next air inlet pipe at the same time. First, perform step (1) until the pressure data of the pressure meter under the current air inlet pipe is the same as the pressure data recorded before the previous air inlet pipe was closed, then repeat steps (2) and (3).

[0015] In the above-mentioned vacuum pump performance test method, before step (1), an initial pipe diameter selection test is performed. Specifically, the vacuum pump to be tested is pumped from large to small according to the size of the inlet pipe. During the test, the opening is adjusted by the valve of the corresponding inlet pipe until the orifice plate flow meter on the inlet pipe displays valid data. Then, it is restored to the initial state and the inlet pipe is used as the initial pipe to enter step (1).

[0016] In the above-mentioned vacuum pump performance testing method, in step (2), the pressure data of the pressure gauge and the volumetric flow rate data of the orifice plate flow meter are collected, both of which are carried out in steady state.

[0017] In the above-mentioned vacuum pump performance testing method, the test platform also includes a frame, and the walls of multiple air intake pipes are connected to the frame. The inlet end of the air intake pipe is located at the upper end of the frame, the outlet end of the air intake pipe is located at the lower end of the frame, and the air intake pipe is connected to the buffer tank through its lower end.

[0018] In the above-mentioned performance testing method for vacuum pumps, the outer wall of the buffer tank has a first connecting pipe that matches the number of inlet pipes, and the inlet pipes are connected to the connecting pipes via flanges; the buffer tank also has a second connecting pipe, which is connected to the vacuum pump under test via flanges; the first connecting pipe also has a thermometer, and the second connecting pipe has a control valve.

[0019] In the above-mentioned vacuum pump performance testing method, the test platform also includes a filter tank and a silencer. The buffer tank and the vacuum pump under test are connected through the filter tank, and the silencer is connected to the vacuum pump's outlet flange through the outlet pipe.

[0020] In the above-mentioned vacuum pump performance testing method, the vacuum pump under test is an oil screw vacuum pump, a rotary vane vacuum pump, a dry oil-free vacuum pump, or a magnetic levitation vacuum pump.

[0021] One of the above-mentioned technical solutions in this application has at least one of the following advantages or beneficial effects:

[0022] 1. This application uses multi-diameter inlet pipes in conjunction with orifice plate flow meters with different measurement ranges, which can make up for the shortcomings of orifice plate flow meters that cannot measure beyond their range. By switching to the next diameter inlet pipe through data feedback from the plate flow meter, the pumping speed performance of the vacuum pump under different pressures can be accurately measured.

[0023] 2. This application uses valves to control the pressure of the buffer tank, combined with segmented testing of multiple pipe diameters, enabling multi-point data acquisition and rapid measurement, ensuring measurement accuracy and the accuracy of the vacuum pump performance curve;

[0024] 3. This application also includes a filter tank to prevent solid particles from entering the vacuum pump and damaging the pump body;

[0025] 4. This application can meet the measurement requirements of various types of vacuum pumps and has good versatility. Attached Figure Description

[0026] The present application will be further described below with reference to the accompanying drawings and embodiments;

[0027] Figure 1 This is the pipeline diagram of the test platform;

[0028] The figure labels for each figure are as follows:

[0029] Inlet pipe 1; orifice plate flow meter 2; buffer tank 3; vacuum pump 4; silencer 5; first inlet pipe 11; second inlet pipe 12; third inlet pipe 13; fourth inlet pipe 14; fifth inlet pipe 15; sixth inlet pipe 16; valve 17; first orifice plate flow meter 21; second orifice plate flow meter 22; third orifice plate flow meter 23; fourth orifice plate flow meter 24; fifth orifice plate flow meter 25; sixth orifice plate flow meter 26; pressure gauge 31; first connecting pipe 32; second connecting pipe 33; control valve 321. Detailed Implementation

[0030] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0031] The following disclosure provides many different implementation methods or examples for different schemes of implementing this application.

[0032] Example 1

[0033] Reference Figure 1 A testing platform includes multiple air inlet pipes 1, the diameter of which decreases sequentially; one end of each air inlet pipe 1 is an air inlet, and the other end is connected to a vacuum pump 4 to be tested via a buffer tank 3; each air inlet pipe 1 is equipped with a valve 17 and an orifice plate flow meter 2; the measurement range of the multiple orifice plate flow meters 2 decreases as the diameter of the air inlet pipe 1 decreases, and the buffer tank 3 is equipped with a pressure gauge 31.

[0034] It should be noted that the structure of the orifice plate flow meter 2 can be found in the Baidu Encyclopedia entry. As it is a standardized component, it does not require calibration before use.

[0035] In this design, multiple air inlet pipes 1 with different diameters, combined with orifice plate flow meters 2 with different measurement ranges, can perform segmented measurement of the pumping speed of the vacuum pump 4. This compensates for the defect that data cannot be collected when the flow rate exceeds the measurement range of the orifice plate flow meter 2. Furthermore, valve 17 is used to regulate the pressure of the buffer tank 3. The principle is that the opening degree of valve 17 determines the rate at which external air flows into the buffer tank 3. When the pumping volume is greater than the inlet volume, the pressure in the buffer tank 3 drops. To maintain a certain pressure, the inlet volume will also be reduced, possibly even to the measurement range of the orifice plate flow meter 2. Therefore, the segmented design allows for switching of the measurement range, enabling accurate measurement of the pumping performance under different vacuum levels.

[0036] Furthermore, there are six intake pipes 1, namely the first intake pipe 11, the second intake pipe 12, the third intake pipe 13, the fourth intake pipe 14, the fifth intake pipe 15, and the sixth intake pipe 16, with the pipe diameters decreasing sequentially from 11 to 16. There are five orifice plate flow meters 2, namely the first orifice plate flow meter 21, the second orifice plate flow meter 22, the third orifice plate flow meter 23, the fourth orifice plate flow meter 24, the fifth orifice plate flow meter 25, and the sixth orifice plate flow meter 26, with the measurement ranges decreasing sequentially and their endpoints coinciding.

[0037] In actual use, not all six intake pipes 1 need to be put into use. It needs to be based on the power of the vacuum pump 4. In addition, a test method can be used to select which one to use as the initial intake pipe 1. Specifically, when the vacuum pump 4 is tested, if the orifice plate flow meter of the first intake pipe 11 has no valid data when the valve 17 is adjusted, and the same is true for the second intake pipe 12, but the third intake pipe 13 starts to have data, then after zeroing and resetting, the third intake pipe 13 is selected as the initial pipe and the performance test begins.

[0038] In a preferred embodiment, the six intake pipes 1 are of the same length.

[0039] The first orifice plate flow meter has a measurement range of 5200 m³ / h to 1300 m³ / h; the second orifice plate flow meter has a measurement range of 2800 m³ / h to 700 m³ / h; the third orifice plate flow meter has a measurement range of 1800 m³ / h to 450 m³ / h; the fourth orifice plate flow meter has a measurement range of 800 m³ / h to 300 m³ / h; the fifth orifice plate flow meter has a measurement range of 460 m³ / h to 92 m³ / h; and the sixth orifice plate flow meter has a measurement range of 100 m³ / h to 20 m³ / h.

[0040] In other words, the first orifice plate flow meter 21 can only test the range of 5200 m³ / h to 1300 m³ / h. Flow data below 1300 m³ / h cannot be detected. Therefore, it is necessary to switch to the second inlet pipe 12 and use the second orifice plate flow meter 22 for measurement. The second orifice plate flow meter 22 can measure the range of 2800 m³ / h to 700 m³ / h and can measure flow data below 1300 m³ / h. However, it cannot measure flow below 700 m³ / h. Therefore, it is necessary to switch to the third inlet pipe 13, and so on.

[0041] In this embodiment, the test platform also includes a frame, and the walls of multiple air intake pipes 1 are all connected to the frame. The inlet end of the air intake pipe 1 is located at its upper end, and the outlet end of the air intake pipe 1 is located at its lower end. The air intake pipe 1 is connected to the buffer tank 3 through its lower end.

[0042] Specifically, the upper end of the air inlet pipe 1 is the air inlet, which is connected to the atmosphere. During the test, the atmosphere enters the buffer tank 3 through the air inlet. At the same time, the outlet end of the air inlet pipe 1 is set at the lower end, so that large components such as the vacuum pump under test 4 and the buffer tank 3 can be placed on the workshop floor, which is convenient for maintenance and replacement of different vacuum pumps under test 4.

[0043] In this embodiment, the outer wall of the buffer tank 3 has a first connecting pipe 32 that matches the number of air inlet pipes 1, and the air inlet pipes 1 and the connecting pipes are connected by a flange; the buffer tank 3 also has a second connecting pipe 33, and the second connecting pipe 33 is connected to the vacuum pump 4 to be tested by a flange; the first connecting pipe 32 also has a thermometer, and the second connecting pipe 33 has a control valve 321.

[0044] Regarding flange connections, this is a standard connection. For details, please refer to the Baidu Encyclopedia entry. Simply put, it refers to a detachable connection consisting of a flange, gasket, and bolts connected together as a combined sealing structure.

[0045] Furthermore, the test platform also includes a filter tank (not shown in the figure) and a silencer 5. The buffer tank 3 and the vacuum pump 4 under test are connected through the filter tank, and the silencer 5 is connected to the outlet flange of the vacuum pump 4 through the outlet pipe.

[0046] Specifically, the filter canister prevents solid particles from the atmosphere from entering the pump body and damaging it. If a vacuum unit with its own filter canister is used, the filter canister inside the vacuum unit is directly connected to the buffer tank 3. Regarding the filter canister, this is prior art in the field; for details, please refer to commercially available vacuum pump filters. Therefore, the specific structure of the filter canister will not be described in detail in this embodiment. The silencer 5 is a pipeline silencer 5, which is well known to those skilled in the art. It should also be noted that the filter canister inevitably introduces flow resistance; therefore, the data measured in this application are data from actual operating conditions.

[0047] In this embodiment, the vacuum pump 4 to be tested is an oil screw vacuum pump, a rotary vane vacuum pump, a dry oil-free vacuum pump, or a magnetic levitation vacuum pump.

[0048] Example 2

[0049] A performance testing method for a vacuum pump, the method relating to the test platform of Example 1; the method includes the following steps:

[0050] Step (1): The buffer tank is connected to the atmosphere through a single air intake pipe. The vacuum pump to be tested operates at a preset speed to extract air from the buffer tank. The pressure inside the buffer tank is controlled by the opening of the valve in the air intake pipe.

[0051] Step (2): Collect the pressure data from the pressure gauge and the volumetric flow rate data from the orifice plate flow meter of the inlet pipe respectively, and construct the vacuum pump performance curve under the current working condition using the pressure data and volumetric flow rate data.

[0052] Step (3): When the data of the orifice plate flow meter of the air inlet pipe is invalid, close the air inlet pipe and switch to the next air inlet pipe at the same time, and repeat steps 1 to 3 until all air inlet pipes are tested; wherein, the diameter of the next air inlet pipe is smaller than the diameter of the previous air inlet pipe.

[0053] Furthermore, when performing step (3), if the data of the orifice plate flow meter of the air inlet pipe is invalid, record the current pressure data, then close the air inlet pipe and switch to the next air inlet pipe at the same time. Perform step (1) first, until the pressure data of the pressure gauge under the current air inlet pipe is the same as the pressure data recorded before the previous air inlet pipe was closed, then repeat steps (2) and (3).

[0054] In this embodiment, in step (1), if the intake pipe used is the intake pipe with the smallest diameter, then when the data of the orifice plate flow meter of the intake pipe is invalid, the intake pipe is closed and the test stops.

[0055] In this embodiment, invalid data for orifice plate flow meters specifically refers to data that is 0.

[0056] In this embodiment, before step (1), an initial pipe diameter selection test is performed. Specifically, the vacuum pump to be tested is tested by pumping air in descending order of the size of the air inlet pipe. During the test, the opening is adjusted by the valve of the corresponding air inlet pipe until the orifice plate flow meter on the air inlet pipe displays valid data. Then, the initial state is restored and the air inlet pipe is used as the initial pipe to enter step (1). In addition, based on the size of the vacuum pump to be tested, those skilled in the art can directly exclude air inlet pipes with large outer diameters.

[0057] In this embodiment, in step (2), the pressure data of the pressure gauge and the volumetric flow rate data of the orifice plate flow meter are collected under steady-state conditions.

[0058] Specifically, regarding steady state, the data acquisition standard for the flow method described in standard number GB / T 40344.1-2021 can be referenced. Regarding the performance curve of the vacuum pump, it is the existing technology in this field. The horizontal axis is the inlet pressure and the vertical axis is the pumping speed. The inlet pressure on the horizontal axis is the data obtained by the pressure gauge, and the pumping speed is calculated by converting the volumetric flow rate data obtained by the orifice plate flow meter using the conversion method described in the above standard number. By collecting pumping speed performance at multiple points under different pressures, the final performance curve of the vacuum pump is obtained by plotting the points and connecting them.

[0059] In step (3), the switching method is based on the pipe diameter of the first intake pipe, the second intake pipe, the third intake pipe, the fourth intake pipe, the fifth intake pipe and the sixth intake pipe.

[0060] In this embodiment, a control system is also included. This control system is a control system well known to those skilled in the art. This control system is used to control the valve control, data conversion, recording of collected data, and to derive the performance curve of the vacuum pump.

[0061] Using the first intake pipe as the initial conduit, the testing principle of this invention is as follows: The buffer tank is connected to the atmosphere through the first intake pipe, and the vacuum pump under test is connected to the buffer tank. The vacuum pump under test operates at a preset speed to extract air from the buffer tank. The opening of the first valve on the first intake pipe controls the rate at which external air flows into the buffer tank. When the pumping volume is greater than the intake volume, the pressure inside the buffer tank decreases. By maintaining a certain pressure, when the pressure and the first orifice plate flow meter are in a steady state, the first pressure data and volumetric flow rate data are acquired, and the pumping speed is determined. The first performance curve of the vacuum pump is plotted. Repeat the above operation to plot points multiple times until, at a certain pressure, the first orifice plate flowmeter reading is 0 due to the reduced airflow. This is considered as the airflow being below the measurement range of the first orifice plate flowmeter. Record the current pressure data. At this point, close the first air inlet pipe and simultaneously open the second air inlet pipe. Control the second valve on the second air inlet pipe to make the pressure in the buffer tank equal to the pressure data before the first air inlet pipe was closed. Test using the second orifice plate flowmeter. Repeat the above operation until the sixth air inlet pipe is closed to complete the measurement and obtain the performance curve of the vacuum pump.

[0062] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements or modifications can be made without departing from the principle of this application, and these improvements or modifications should also be considered within the scope of protection of this application.

Claims

1. A method of testing the performance of a vacuum pump, characterized in that, The method relates to a test platform, the test platform comprising a plurality of air inlet pipes, the pipe diameters of the plurality of air inlet pipes being sequentially reduced; one end of the plurality of air inlet pipes is an air inlet end, and the other end is communicated with a vacuum pump to be tested through a same buffer tank; a valve and an orifice plate flowmeter are arranged on the plurality of air inlet pipes; the measurement ranges of the plurality of orifice plate flowmeters are reduced along with the reduction of the pipe diameters of the air inlet pipes; the buffer tank is provided with a pressure gauge; and the method comprises the following steps: Step (1): the buffer tank is communicated with the atmosphere through a single air inlet pipe, and the vacuum pump to be tested is operated at a preset rotating speed to extract air in the buffer tank, and the air inlet pipe controls the pressure in the buffer tank through the opening degree of the valve; Step (2): pressure data of the pressure gauge and volume flow data of the orifice plate flowmeter of the air inlet pipe are collected respectively, and a vacuum pump performance curve diagram under a current working condition is constructed through the pressure data and the volume flow data; Step (3): when the data of the orifice plate flowmeter of the air inlet pipe is invalid data, the air inlet pipe is closed and the next air inlet pipe is switched, and steps (1)-(3) are performed again until the test of all the air inlet pipes is completed; wherein the pipe diameter of the next air inlet pipe is smaller than that of the previous air inlet pipe.

2. The performance test method of a vacuum pump according to claim 1, characterized in that, In the step (1), if the air inlet pipe adopted is the air inlet pipe with the smallest pipe diameter, when the data of the orifice plate flowmeter of the air inlet pipe is invalid data, the air inlet pipe is closed, and the test is stopped.

3. The method of claim 1, wherein The air inlet pipes are six, which are a first air inlet pipe, a second air inlet pipe, a third air inlet pipe, a fourth air inlet pipe, a fifth air inlet pipe and a sixth air inlet pipe, the pipe diameters of the first air inlet pipe, the second air inlet pipe, the third air inlet pipe, the fourth air inlet pipe, the fifth air inlet pipe and the sixth air inlet pipe are sequentially reduced; the orifice plate flowmeters are five, which are a first orifice plate flowmeter, a second orifice plate flowmeter, a third orifice plate flowmeter, a fourth orifice plate flowmeter, a fifth orifice plate flowmeter and a sixth orifice plate flowmeter; the measurement ranges of the first orifice plate flowmeter, the second orifice plate flowmeter, the third orifice plate flowmeter, the fourth orifice plate flowmeter, the fifth orifice plate flowmeter and the sixth orifice plate flowmeter are sequentially reduced and the end points coincide; the number of the valves matches the number of the air inlet pipes; In the step (3), the switching mode is that the pipe diameters of the first air inlet pipe, the second air inlet pipe, the third air inlet pipe, the fourth air inlet pipe, the fifth air inlet pipe and the sixth air inlet pipe are taken as the sequential reference.

4. The method of claim 3, wherein The first orifice plate flowmeter has a measurement range of 5200m3 / h-1300m3 / h; the second orifice plate flowmeter has a measurement range of 2800m3 / h-700m3 / h; the third orifice plate flowmeter has a measurement range of 1800m3 / h-450m3 / h; the fourth orifice plate flowmeter has a measurement range of 800m3 / h-300m3 / h; the fifth orifice plate flowmeter has a measurement range of 460m3 / h-92m3 / h; and the sixth orifice plate flowmeter has a measurement range of 100m3 / h-20m3 / h. The step (3) is specifically: when the data of the orifice plate flowmeter of the intake pipeline is invalid data, the current pressure data is recorded, then the intake pipeline is closed and the next intake pipeline is switched, step (1) is performed first, until the pressure data of the pressure gauge under the current intake pipeline is the same as the pressure data recorded before the last intake pipeline is closed, then steps (2) and (3) are performed again.

5. The method of claim 1, wherein Before step (1) is performed, an initial pipe diameter selection test is performed, specifically, the vacuum pump to be tested is tested by air pumping in sequence from large to small according to the size of the intake pipeline, during the test, the opening degree of the valve corresponding to the intake pipeline is adjusted until the orifice plate flowmeter on the intake pipeline displays valid data, then the initial state is restored, and the intake pipeline is used as the initial pipeline to enter step (1).

6. The method of claim 1, wherein In step (2), the pressure data of the pressure gauge and the volumetric flow data of the orifice plate flowmeter are collected, both of which are collected in a steady state.

7. The method of claim 1, wherein The test platform further comprises a rack, the walls of the plurality of intake pipelines are connected to the rack, the inlet end of the intake pipeline is located at the upper end thereof, the outlet end of the intake pipeline is located at the lower end thereof, and the intake pipeline is in communication with the buffer tank through the lower end thereof.

8. The method of claim 1, wherein The outer wall of the buffer tank has a first connecting pipe matched with the number of the intake pipelines, the intake pipeline is connected to the connecting pipe through a flange; the buffer tank further has a second connecting pipe, the second connecting pipe is connected to the vacuum pump to be tested through a flange, the first connecting pipe further has a thermometer, and the second connecting pipe has a control valve.

9. The method of claim 1, wherein The test platform further comprises a filter tank and a silencer, the buffer tank and the vacuum pump to be tested are in communication through the filter tank, and the silencer is connected to the gas outlet flange of the vacuum pump through a gas outlet pipeline.

10. The method of claim 1, wherein The vacuum pump to be tested is an oil screw vacuum pump, a rotary vane vacuum pump, a dry oil-free vacuum pump or a magnetic suspension vacuum pump.

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