A flexible pipe joint isolation performance test method based on a pipe system

Abstract

The application discloses a kind of flexible pipe vibration isolation performance test method based on pipeline system, according to the actual connection of flexible pipe pipeline system, corresponding test pipeline, pipeline flange, test support and flexible pipe flange are made with input end pipeline and output end pipeline, flexible pipe is accessed and the test pipeline system that can simulate actual pipeline system is obtained, then by different frequency excitation is applied to test pipeline system, and the input end response and output end response of flexible pipe under different excitation frequency are recorded respectively, so as to calculate the displacement vibration level difference, velocity vibration level difference and acceleration vibration level difference of flexible pipe under different excitation frequency, and the average displacement vibration level difference, average velocity vibration level difference and average acceleration vibration level difference in excitation frequency range, the vibration isolation performance of flexible pipe can be evaluated, the vibration isolation performance in the pipeline system that flexible pipe accesses can be truly simulated, and the vibration level difference parameter of flexible pipe is accurately tested.

Description

Technical Field

[0001] This invention relates to the field of flexible fittings, and more particularly to a test method for the vibration isolation performance of flexible fittings in pipeline systems. Background Technology

[0002] Flexible joints consist of one or more bellows connected in series in a piping system, primarily serving to compensate for displacement and reduce vibration. The vibration isolation performance of flexible joints is mainly measured by the vibration level drop parameter. This parameter is related to the piping system to which the flexible joint is connected; parameters such as the stiffness and mass distribution of the piping system, and external supports all affect the vibration level drop. Therefore, vibration level drop tests are only meaningful if the influence of the actual connected piping system is considered. Currently, vibration level drop tests for flexible joints only consider the flexible joint itself and do not take into account the influence of the connected piping system. Therefore, existing test methods cannot realistically simulate the vibration isolation performance of flexible joints in actual working piping systems and cannot accurately measure the vibration level drop parameter of flexible joints. Summary of the Invention

[0003] This invention provides a test method for the vibration isolation performance of flexible connectors in pipeline systems, which can realistically simulate the vibration isolation performance of flexible connectors connected to pipeline systems and accurately test the vibration level drop parameters of flexible connectors.

[0004] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a test method for the vibration isolation performance of a flexible connector based on a pipeline system, wherein the pipeline system includes an input pipe and an output pipe, the input pipe is installed on at least two external supports, and one end of the input pipe is connected to the input end of the flexible connector, and the output pipe is also installed on at least two external supports, and one end of the output pipe is connected to the output end of the flexible connector. The method includes the following steps:

[0005] Step 1: Cut a length from the input pipe as the length of the input test pipe. The cut length shall not be less than the axial distance between two adjacent external supports on the input pipe. Then, make an input test pipe with the same material and structure as the input pipe within the cut length range.

[0006] A section of length is cut off from the output pipe as the length of the output test pipe. The cut-off length is not less than the axial distance between two adjacent external supports on the output pipe. Then, an output test pipe with the same material and structure as the output pipe within the cut-off length range is made.

[0007] Step 2: Calculate the mass of the medium inside the input pipe and the mass of the input pipe outside the cut length range. Sum the two calculated masses as the total mass of the two flanges. Make two input pipe flanges with the same material and structure. Then fix the two input pipe flanges to both ends of the input test pipe respectively.

[0008] Calculate the mass of the medium inside the output pipe and the mass of the output pipe outside the cut length range, respectively. Take the sum of the two calculated masses as the total mass of the two flanges, make two output pipe flanges with the same material and structure, and then fix the two output pipe flanges to both ends of the output test pipe respectively.

[0009] Step 3: Install the input test pipe on two test supports. The contact position, contact area and contact surface material between the two test supports and the input test pipe should be consistent with the two adjacent external supports within the cut length range of the input pipe.

[0010] The output test pipe is also installed on the two test supports. The contact position, contact area and contact surface material between the two test supports and the output test pipe are consistent with the two adjacent external supports within the cut length range of the output pipe.

[0011] Step 4: Calculate the mass of the medium inside the flexible connector, and use this calculated mass as the total mass of the two flanges. Make two flexible connector flanges with the same material and structure, and then fix the two flexible connector flanges to both ends of the flexible connector respectively.

[0012] Step 5: Install the flexible connector between the input test pipe and the output test pipe. Connect one flexible connector flange to the corresponding input pipe flange using a bolt connection assembly, and connect the other flexible connector flange to the corresponding output pipe flange using the same bolt connection assembly. Then, connect the vibrator to the end of the input test pipe away from the flexible connector. Set an input sensor at the end of the flexible connector closer to the input test pipe, and set an output sensor at the end of the flexible connector closer to the output test pipe.

[0013] Step 6: Within the set excitation frequency range, apply multiple excitations of different frequencies through the vibrator, collect the detection data of the input sensor as the input response, and collect the detection data of the output sensor as the output response, to obtain the input displacement response, output displacement response, input velocity response, output velocity response, input acceleration response, and output acceleration response of the flexible tube at different excitation frequencies.

[0014] Step 7: Calculate the displacement level drop ratio, velocity level drop ratio, and acceleration level drop ratio corresponding to multiple different excitation frequencies based on the input and output responses. Then, calculate the displacement level drop, velocity level drop, and acceleration level drop corresponding to multiple different excitation frequencies based on the level drop ratios.

[0015] Step 8: Sum the multiple displacement level differences corresponding to different excitation frequencies, and then divide by the excitation frequency bandwidth to obtain the average displacement level difference within the excitation frequency range; sum the multiple velocity level differences corresponding to different excitation frequencies, and then divide by the excitation frequency bandwidth to obtain the average velocity level difference within the excitation frequency range; sum the multiple acceleration level differences corresponding to different excitation frequencies, and then divide by the excitation frequency bandwidth to obtain the average acceleration level difference within the excitation frequency range.

[0016] Step 9: Evaluate the vibration isolation performance of the flexible joint based on the displacement level difference, velocity level difference, and acceleration level difference of the flexible joint at different excitation frequencies, as well as the average displacement level difference, average velocity level difference, and average acceleration level difference within the excitation frequency range. This completes the vibration isolation performance test of the flexible joint.

[0017] Preferably, the vibration level drop ratio p The general formula is:

[0018] In the formula, A1 is the displacement, velocity, or acceleration at the input end of the flexible connector, and A2 is the displacement, velocity, or acceleration at the output end of the flexible connector.

[0019] The general formula for vibration level drop is: ;

[0020] The general formula for the average vibration level drop is:

[0021] R is the excitation frequency bandwidth.

[0022] According to the above technical solution, the beneficial effects of the present invention are:

[0023] This invention, based on the actual piping system connected by a flexible connector, manufactures test pipes, pipe flanges, and test supports corresponding to the input and output pipes. It also considers the mass of the internal medium of the flexible connector when manufacturing the flexible connector flange, thus creating a test piping system capable of simulating the actual piping system. By applying excitations of different frequencies to the test piping system and recording the input and output responses of the flexible connector at different excitation frequencies, the displacement level difference, velocity level difference, and acceleration level difference of the flexible connector at different excitation frequencies, as well as the average displacement level difference, average velocity level difference, and average acceleration level difference within the excitation frequency range, can be calculated. This allows for the evaluation of the vibration isolation performance of the flexible connector, enabling the vibration isolation performance test to realistically simulate the vibration isolation performance of the flexible connector connected to the piping system. It accurately measures the vibration level difference parameters of the flexible connector, allowing designers to use these parameters to correct the vibration isolation performance design of the flexible connector, providing an important basis for the design of flexible connectors. Detailed Implementation

[0024] This invention provides a test method for the vibration isolation performance of a flexible connector based on a pipeline system. The pipeline system includes an input pipe and an output pipe. The input pipe is installed on at least two external supports, and one end of the input pipe is connected to the input end of the flexible connector. The output pipe is also installed on at least two external supports, and one end of the output pipe is connected to the output end of the flexible connector. The method includes the following steps.

[0025] Step 1: Cut a section of length from the input pipe as the length of the input test pipe. The cut length should not be less than the axial distance between two adjacent external supports on the input pipe. Then, fabricate an input test pipe with the same material and structure as the input pipe within the cut length range.

[0026] A section of the output pipe is cut off as the length of the output test pipe. The cut-off length is not less than the axial distance between two adjacent external supports on the output pipe. Then, an output test pipe with the same material and structure as the output pipe within the cut-off length range is made.

[0027] Step 2: Calculate the mass of the medium inside the input pipe and the mass of the input pipe outside the cut length range. Sum the two calculated masses as the total mass of the two flanges. Make two input pipe flanges with the same material and structure, and then fix the two input pipe flanges to both ends of the input test pipe respectively.

[0028] Calculate the mass of the medium inside the output pipe and the mass of the output pipe outside the cut length range, respectively. Sum the two calculated masses as the total mass of the two flanges. Make two output pipe flanges with the same material and structure, and then fix the two output pipe flanges to both ends of the output test pipe.

[0029] Step 3: Install the input test pipe on two test supports. The contact position, contact area, and contact surface material between the two test supports and the input test pipe should be consistent with the two adjacent external supports within the cut length range of the input pipe, so that the input test pipe and the input pipe within the cut length range can obtain the same support effect.

[0030] The output test pipe is also installed on two test supports. The contact position, contact area and contact surface material between the two test supports and the output test pipe are consistent with the two adjacent external supports within the cut length range of the output pipe, so that the output test pipe and the output pipe within the cut length range obtain the same support effect.

[0031] Step 4: Calculate the mass of the medium inside the flexible nozzle, and use this calculated mass as the total mass of the two flanges. Make two flexible nozzle flanges with the same material and structure, and then fix the two flexible nozzle flanges to both ends of the flexible nozzle respectively.

[0032] Step 5: Install the flexible connector between the input and output test pipes. Connect one flexible connector flange to the corresponding input pipe flange using a bolt connection assembly, and connect the other flexible connector flange to the corresponding output pipe flange using the same bolt connection assembly. Then, connect the vibrator to the end of the input test pipe furthest from the flexible connector. Set an input sensor at the end of the flexible connector closest to the input test pipe, and set an output sensor at the end of the flexible connector closest to the output test pipe.

[0033] Step Six: Within the set excitation frequency range, apply multiple excitations of different frequencies through the exciter, collect the detection data of the input sensor as the input response, and collect the detection data of the output sensor as the output response. Both the input and output sensors include a displacement sensor, a velocity sensor, and an acceleration sensor, thereby obtaining the input displacement response, output displacement response, input velocity response, output velocity response, input acceleration response, and output acceleration response of the flexible tube at different excitation frequencies.

[0034] Step 7: Calculate the displacement level drop ratio, velocity level drop ratio, and acceleration level drop ratio corresponding to multiple different excitation frequencies based on the input and output responses.p The general formula is:

[0035] In the formula, A1 is the displacement, velocity, or acceleration at the input end of the flexible connector, and A2 is the displacement, velocity, or acceleration at the output end of the flexible connector.

[0036] Then, based on the vibration level drop ratio, the displacement vibration level drop, velocity vibration level drop, and acceleration vibration level drop corresponding to multiple different excitation frequencies are calculated. The general formula for vibration level drop is: .

[0037] Step 8: Sum the multiple displacement level drops corresponding to different excitation frequencies, and then divide by the excitation frequency bandwidth to obtain the average displacement level drop within the excitation frequency range.

[0038] The average velocity level drop within the excitation frequency range is obtained by summing the multiple velocity level drops corresponding to different excitation frequencies and then dividing by the excitation frequency bandwidth.

[0039] The summation of multiple acceleration level drops corresponding to different excitation frequencies is then divided by the excitation frequency bandwidth to obtain the average acceleration level drop within the excitation frequency range.

[0040] The general formula for the average vibration level drop is:

[0041] R is the excitation frequency bandwidth.

[0042] Step 9: Evaluate the vibration isolation performance of the flexible joint based on the displacement level difference, velocity level difference, and acceleration level difference of the flexible joint at different excitation frequencies, as well as the average displacement level difference, average velocity level difference, and average acceleration level difference within the excitation frequency range. This completes the vibration isolation performance test of the flexible joint.

[0043] Since the test pipes, pipe flanges, test supports, and flexible nozzle flanges are all manufactured based on the actual pipe system connected by the flexible nozzle, the test pipe system can simulate the actual pipe system. This allows for accurate testing of the input and output responses of the flexible nozzle at different excitation frequencies, thereby accurately measuring the vibration level drop parameters of the flexible nozzle. Designers can then use these vibration isolation performance parameters to correct the vibration isolation performance design of the flexible nozzle, providing an important basis for the design of the flexible nozzle.

Claims

1. A method for testing the vibration isolation performance of a flexible pipe based on a piping system, the piping system including an input end pipe and an output end pipe, the input end pipe being mounted on at least two external supports and one end of the input end pipe being connected to an input end of the flexible pipe, the output end pipe also being mounted on at least two external supports and one end of the output end pipe being connected to an output end of the flexible pipe, characterized in that, The method comprises the following steps: Step one, cut a length of the input pipeline as the length of the input test pipeline, the length is not less than the axial distance between the two adjacent external supports on the input pipeline, then make the input test pipeline with the same material and the same structure as the input pipeline within the length range; Cut a length of the output pipeline as the length of the output test pipeline, the length is not less than the axial distance between the two adjacent external supports on the output pipeline, then make the output test pipeline with the same material and the same structure as the output pipeline within the length range; Step two, calculate the mass of the medium in the input pipeline and the mass of the input pipeline outside the length range, and the sum of the two masses as the total mass of the two flanges, then make two input pipeline flanges with the same material and the same structure, and then fix the two input pipeline flanges on the two ends of the input test pipeline respectively; Calculate the mass of the medium in the output pipeline and the mass of the output pipeline outside the length range, and the sum of the two masses as the total mass of the two flanges, then make two output pipeline flanges with the same material and the same structure, and then fix the two output pipeline flanges on the two ends of the output test pipeline respectively; Step three, install the input test pipeline on the two test supports, the contact position, contact area and contact surface material of the two test supports with the input test pipeline are consistent with the adjacent two external supports within the length range of the input pipeline; Install the output test pipeline on the two test supports, the contact position, contact area and contact surface material of the two test supports with the output test pipeline are consistent with the adjacent two external supports within the length range of the output pipeline; Step four, calculate the mass of the medium in the flexible connector, and the mass as the total mass of the two flanges, then make two flexible connector flanges with the same material and the same structure, and then fix the two flexible connector flanges on the two ends of the flexible connector respectively; Step five, install the flexible connector between the input test pipeline and the output test pipeline, connect one flexible connector flange with the corresponding input pipeline flange through the bolt connection assembly, and connect the other flexible connector flange with the corresponding output pipeline flange through the bolt connection assembly, then connect the exciter on the end of the input test pipeline away from the flexible connector, set the input sensor on the end of the flexible connector close to the input test pipeline, and set the output sensor on the end of the flexible connector close to the output test pipeline; Step six, within the set excitation frequency range, apply multiple excitations with different frequencies through the exciter, collect the detection data of the input sensor as the input response, and collect the detection data of the output sensor as the output response, and obtain the input end displacement response, output end displacement response, input end speed response, output end speed response, input end acceleration response and output end acceleration response of the flexible connector under different excitation frequencies respectively. Step seven, the displacement vibration level difference ratio, the speed vibration level difference ratio and the acceleration vibration level difference ratio corresponding to the plurality of different excitation frequencies are calculated according to the input end response and the output end response, and then the displacement vibration level difference, the speed vibration level difference and the acceleration vibration level difference corresponding to the plurality of different excitation frequencies are calculated according to the vibration level difference ratio; Step eight, the plurality of displacement vibration level differences corresponding to the different excitation frequencies are summed up and then divided by the excitation frequency bandwidth to obtain the average displacement vibration level difference in the excitation frequency range; the plurality of speed vibration level differences corresponding to the different excitation frequencies are summed up and then divided by the excitation frequency bandwidth to obtain the average speed vibration level difference in the excitation frequency range; the plurality of acceleration vibration level differences corresponding to the different excitation frequencies are summed up and then divided by the excitation frequency bandwidth to obtain the average acceleration vibration level difference in the excitation frequency range; Step nine, the vibration isolation performance of the flexible pipe is evaluated according to the displacement vibration level difference, the speed vibration level difference and the acceleration vibration level difference of the flexible pipe at different excitation frequencies, and the average displacement vibration level difference, the average speed vibration level difference and the average acceleration vibration level difference in the excitation frequency range, that is, the vibration isolation performance test of the flexible pipe is completed.

2. The method for testing the vibration isolation performance of a flexible pipe section based on a pipe system according to claim 1, characterized in that: level difference ratio p The general formula is: where A1 is the displacement or velocity or acceleration of the input end of the flexible pipe and A2 is the displacement or velocity or acceleration of the output end of the flexible pipe. The general formula for the level drop is: ; The general formula of the average vibration level difference is: R is the excitation frequency bandwidth.