Research On Cyclone Inlet Pressure And Suspension Density In Dense Medium Coal Preparation

In dense medium coal preparation,the ash content of clean coal is usually controlled by controlling the density of suspension.The density control lag of suspension is large,and the control effect of ash content is poor.Because the density of suspension needs to be adjusted according to ash content of clean coal,the pressure will change continuously under the same speed of mixing pump,and the high height of transmission pipeline will result in unstable inlet pressure of cyclone.Aiming at the unstable inlet pressure of cyclone,this paper adopts the method of fuzzy control to control the inlet pressure of cyclone.Taking the error of pressure and the error change of pressure as the analog input and the output frequency of the converter as the fuzzy output,the m,embership function of the converter is determined according to the field experience and the control rules are established.The precise output of the fuzzy controller is obtained by fuzzy reasoning and de-fuzzification.The simulation of fuzzy control using MATLAB shows that the method of fuzzy control can realize the steady control of the inlet pressure of cyclone.Aiming at the lag of density control,this paper uses dynamic matrix(DMC)prediction algorithm to improve it.The corresponding transfer function is established by parameter identification method,and feedforward compensation decoupling control and dynamic matrix prediction algorithm based on quadratic programming constrained optimization algorithm are adopted for the established model.The simulation results show that DMC prediction algorithm is better in regulating time and overshoot.By controlling the inlet pressure of cyclone and adjusting the density of suspension,the dynamic performance of density control is improved and the lag of density control is improved.