Study On Flow Field Characteristics Of Check Valve

Pump-Valve-Pipeline is an important part of the power plant.The vibration of this system brings harm to itself,and also leads to the safe troubles and noise of other parts.As an important over-flow unit,the check valve is complex,adjusting unavailable and fluctuant,resulting in oscillation problems seriously.In this paper,the problem of abnormal fluctuation in internal flow-field for this check valve is studied.The study is to explore the characteristics of the internal flow field and fluctuation.Especially,the characteristics of internal flow field and the abnormal fluctuations are concerned during the spool movement process.The specific study is as follows:Firstly,the geometrical model,the finite element model and the flow field model of the check valve are constructed.Through using the dry mode test method and the boundary correction method,the installation boundary conditions are obtained smoothly.In addition,the inherent characteristics of the working condition are obtained by calculating the wet model using this boundary condition,which lay the foundation for the influence of the structural characteristics boundary on the fluctuation of the valve during the subsequent opening process.Secondly,the three-dimensional steady and unsteady flow-field models in the valve are established by fluent software.Also,the over-flow characteristics of the valve are calculated.With regard to the different openings and operating conditions,the steady flow-field pressure,variable velocity,forced law and unsteady flow-induced fluctuation characteristics of the valve are analyzed.Meanwhile,the effect of the actual boundary conditions on the internal flow field and the moving parts forced law of the valve are considered.Furthermore,the pressure fluctuation time and frequency characteristic curves of inlet,valve and outlets are obtained.The results are compared with the experimental data,which verifies the correctness of the theoretical results.Finally,based on the UDF dynamic grid technology,the transient motion law equation of the spool moving parts is established.As the fluid moving boundary,the transient motion analysis model of the check valve is constructed to realize the dynamic simulation of the valve group opening process,which is consistent with the test results.The vibration characteristics for the valve with different spring stiffness,spool force form,the actual boundary and structure boundary are studied,which can provide guidance forthe regulation of the valve group in the system.