| As the fluid control and metering components,valves and flowmeters play an important role in the petrochemical industry,energy transmission,water conservancy and hydropower industries.In the practical application of valves and flowmeters,there is not enough space to ensure the requirements of straight pipes length.The measurement precision of flowmeter has been affected by the fluid disturbance inside of the flowmeter.It's difficult to achieve the purpose of precise control and precision measurement.The metering valve which mainly consists of sleeve regulating valve and swirlmeter is selected as the research objects in this paper.The flow resistance characteristics,metrological characteristics and internal flow characteristics are analyzed by using the numerical simulation and experimental study.The further improvement of metering valve is studied in order to improve metering accuracy.The main research contents are as follows:(1)The metering valves three-dimensional model of internal flow is established by Solidworks software.The Gambit software is used to divide the flow passage of flowmeter valve.By comparing several turbulence models,the RNG ?-? turbulence model which suitable for this study is selected,and the numerical simulation of internal flow in the metering valve is carried out by using FLUENT software.And the test-bed is built to research the metering valves characteristics.The flow resistance characteristics,metrological characteristics and internal flow characteristics of metering valve are analyzed under different inlet velocity and valve opening.(2)The interaction between sleeve regulating valve and swirlmeter are analyzed by numerical simulation and experimental study.Under different inlet velocity,the variation law of resistance coefficient and flow coefficient with the valve open degree is analyzed,the effect of the installation position of the valve and flowmeter on the measurement accuracy is studied,the cause of measurement error of metering valve is analyzed through internal flow characteristics.According to the characteristics of sleeve regulating valve and swirlmeter,we hope that the valve is installed upstream of the flowmeter.(3)Improvement study of metering valve has been studied in order to improve the measuring precision,the fluid disturbance upstream of swirlmeter is reduced by increasing the straight pipe inside the metering valve,the reasonable improvement scheme is given.Theimproved metering valve has a considerable degree of improvement in metrological characteristics and stability of the internal flow.The accuracy of the numerical simulation results is verified by the experimental study which reveals the feasibility of the development and research of metering valve. |
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