Design Of Anti Surge Control System Of Centrifugal Air Compressor

The compressed air has been widely used in modern metallurgy,petrochemical,pharmaceutical,food and other industries.Air compressor as the production equipment of compressed air has the characteristics of nonlinear and time variation,so it is difficult to establish a precise mathematical model.The surge is a characteristic of centrifugal compressor inherent,in the production operation,the compressor surge once the situation may cause the compressor was seriously damaged,and even to the whole production system will bring unpredictable losses.So the centrifugal air compressor anti surge control has been an important research direction of the scholars at home and abroadIn this thesis,a company of air compressor project as experimental background,field data collection,using the least squares method to fit the surge line under different speed compressor.Based on the fixed limit flow and variable limit flow method,designed the anti surge control system of air compressor test under the background of the.The central idea of this scheme is that the flow rate of the inlet is always greater than a certain value,which is used as the setting value of the speed range.This scheme requires only the surge point of speed is calculated,does not need to establish accurate mathematical model,simple and convenient easy to be accepted by the technical personnel at the scene.Fuzzy control technology is a new science.It has been widely used in the field of intelligent control,such as machinery,metallurgy,chemical industry,medicine and so on.The surge is an inherent property of the compressor,compressor anti surge control is a complicated process,the traditional PID controller has some limitations on it.This thesis adopts the fuzzy control technology,the error and the error change between the gas and the amount of the setting rate as input to construct a two-dimensional fuzzy controller,the error and the error change between the input and the set amount rate of the fuzzy controller is constructed,the anti surge control scheme of compressor is proposed.And using the fuzzy toolbox of MATLAB software and Simulink to simulate it.By comparing the unit step response of PID controller and fuzzy controller,it can be concluded that the effect of fuzzy controller is better.Finally the experimental results show that:The system can judge the running condition of the compressor inlet flow of time in the actual operation of the compressor,can effectively avoid the occurrence of air compressor surge condition,bring greater economic benefits to the user.