Study On Regulating&Controlling Method Of Composite Regulating-mixing Gas Seal

In recent years,operating condition of large-scale compressor groups is more and more serious,such as high pressure,high speed and high or low temperature.Under these conditions,it is very important that significant factors that whether they can operate stably or regulate and control in time for gas seal.Comparing with the traditional seals,the Composite Regulating-Mixing Gas Seal(short for CR-MGS)not only shows the advantages like low leakage rate and long operational life,but also owns anti-interference,regulating&controlling,which meets the strategy of "Innovation-driven and green development" of "China manufacture 2025".Data simulating calculation and experimental verification of CR-MGS are discussed systematically and thoroughly in this paper,in order to study its steady-state and dynamic regulating&controlling performance,as well as its regulating&controlling method.Analytical model of steady-state regulating&controlling performance has been established,steady-state equation has been solved and FEM calculation of steady-state performance parameters have been completed.The changing rules of steady-state performance parameters have been analyzed,including gas film thickness,gas film stiffness,inner leakage rate,frictional power consumption and axial compensational force,when supplying regulation(short for SR)and closing regulation(short for CR)single and Composite acting.Appropriate control interval has been obtained preliminarily under the given conditions.Analytical model of dynamic regulating&controlling performance has been established,perturbation equation has been solved and FEM calculation of dynamic performance parameters has been completed.The changing rules of dynamic performance parameters with rotating speed and medium pressure have been analyzed,including dynamic stiffness and damping,when under different disturbance.The results of symmetry and decoupling about dynamic stiffness and damping have been proved.The changing rules of dynamic performance parameters of CR-MGS have been analyzed under different supplying and closing regulations single and Composite acting,which optimize regulating&controlling interval.The following performance of CR-MGS has been improved on some degree,when adding closing regulation.Based on analysis of steady-state and dynamic regulating&controlling performance of CR-MGS,the rank of regulating ability and precision have been proposed.Based on mind of RSM,weight distribution scheme of supplying and closing regulation has been proposed,aiming at gas film thickness,inner leakage rate,and axial compensational force,under different perturbation conditions.The BP neural network based on MEA and PID regulating scheme based on fuzzy control have been established.Double composite control method(short for DCRCM)has been accomplished for the foundation of Composite regulating&control scheme of supplying and closing regulation and composite control measure combined with MEA and F-PID,and regulating and control process has been obtained.The CR-MGS is designed and manufactured,and the auxiliary air supply system is also constructed.The regulating&controlling experiment has been conducted under the conditions of supplying and closing regulation,in order to verify the validity of theoretical results.The Composite composite regulating&controlling experiment has been conducted aiming at gas film thickness,in order to verify the feasibility accuracy and rapidity of DCRCM.The research on steady-state and dynamic regulating&controlling performance of CR-MGS contributes to the development of gas seal field.The DCRCM,which is proposed and verified,promotes engineering application of CR-MGS,which contributes to the intelligent development of large-scale compressor group.