Research On Butterfly Valve-type Water Flow Fluctuation Generator

During the actual measurement of the flow,different flow fluctuations will occur in the pipeline,which will affect the measurement results.In order to study the influence of different flow fluctuations on the pipeline measurement results,a butterfly valve flow fluctuation generator was designed in this paper.The butterfly valve was oscillated back and forth by the motor to form a flow fluctuation in the pipeline.The generator can change the swing frequency and swing angle of the motor to produce different flow fluctuations.Experiments have shown that the flow fluctuation generated by fluctuation generator can propagate along the upstream and downstream of the pipeline,and when the generator swing frequency and swing angle are changed,the flow fluctuation generated will also change.The main contents of this paper are as follows:(1)By researching and comparing the advantages and disadvantages of existing wave generators,combined with the existing water flow experiment in the China Institute of Metrology,and in order to simulate the flow fluctuations that may occur in the pipeline,a variable frequency and variable amplitude can be designed.,waveformchanging flow fluctuation generator.(2)The LABVIEW is used to program the motor control system.The control system mainly includes four modules: the valve opening module,the continuous swing module,the intermittent swing module and the square wave swing module.The motor swings through the coupling control the butterfly valve below,which can produce different Continuous fluctuations in the swing frequency,swing amplitude,or discontinuous fluctuations,or fluctuations in different waveforms.(3)Experiments are carried out on the quality of the generator.The experiment is divided into static experiment and dynamic experiment.The swing frequency,swing amplitude,valve opening and generator position of the generator are changed.The actual flow fluctuation is measured by the pressure sensor.Compare the set flow fluctuations with the actual flow fluctuations to evaluate the designed flow fluctuation generator.(4)Summarizing the research content,the device has better flow fluctuation effect in the low frequency range,and the flow fluctuation effect is poor when the swing frequency is high.It also provides a research basis for the accuracy of flowmeter measurement for subsequent flow fluctuations,and prospects for future research.