| The valve-flow piping system occupies is a very important position in industrial process control,and its overall dynamic characteristics affect the performance of the entire industrial control process.In order to analyze the nonlinear coupling vibration characteristics of the pipeline system and the influence on the vibration characteristics of the valve body,this paper analyzes the characteristics of the pipeline system and the valve system independently based on the transfer matrix method,and analyzes the overall characteristics of the valve-Mainly completed the following three parts of the work.(1)In order to analyze the nonlinear coupling dynamics behavior of the pipeline system,the dynamic equation of the piping system,the friction coupling between the pipeline and the liquid and the Poisson coupling equation are considered.The Galerkin method and the time-discrete method of the multi-body system are established.The results show that the coupling nonlinear factors increase the other components except the natural frequency components,and the flow rate is 0-7,The system is more obvious when the quasi-periodic motion,when the dimensionless flow rate continues to increase,the system vibration amplitude changes rapidly,there divergence,instability situation.(2)In order to study the influence of nonlinear fluid force and frictional force on the vibration of the valve spool,a differential equation of motion of the single-seat valve-type valve spool system is established.The inherent characteristics of the spool system under different working conditions are numerically solved.The dynamic response is coMPared with the linear model.The results show that the pressure of the valve spool system increases with the increase of the pressure difference,and the fluid force increases and the spool displacement increases.Given the pressure difference,with the opening degree increases,the natural frequency of the spool system decreases,the fluid force decreases,the smaller the spool displacement;the same conditions,consider the nonlinear factors to calculate the fluid force and friction The linear model calculates the fluid force and the offset,so the nonlinear factors must be taken into account in the design of the control valve.(3)In order to study the coupling dynamic characteristics of the control valve-flow piping system,the transfer matrix model of the whole system of the control valve-flow pipeline is established based on the transfer matrix model of the control valve and the pipeline system.The vibration characteristics of the spool are analyzed under different working conditions And no pipe control valve spool vibration characteristics were coMPared.The results show that the trend of fluid force and offset of the spool system with piping control valve is the same as that of the non-ducted spool.The influence of the pipeline on the fluid pressure state of the valve inlet makes the dynamic behavior of the spool motion changed from single-cycle stable motion to Quasi-periodic motion increases the instability of the spool motion,so the effect of the pipe on the valve should be taken into account in the control valve control. |
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