Research On Boiler Water Level Control System Of CDQ

Coke Dry Quenching's boiler is a kind of pressure and directly heated special type equipment,is a common equipment in industrial production.The security problem of boiler is a very important issue,the most common accidents in industrial boiler:the lack water in pot,boiler over pressure,the pot full of water,proton total soda,furnace tube blasting,furnace chamber blasting,the twice combustion,boiler fire extinguished etc.Among them the highest proportion of boiler lack water accidents.Most of these accidents originate from improper control of boiler water level,visible,the importance of the boiler drum liquid level control in the boiler device control system.Tracking the boiler evaporation capacity and maintaining drum water level the process within the allowable range of technician,is the necessary condition to ensure the safety of boiler operation,is also the main indexes of boiler normal production operation.The measuring instruments and measuring methods of all kinds of drum level are introduced in this paper.Through the analysis of the research on various measuring instruments and measuring method,find out the scene suitable process conditions of the drum water level monitoring instrument and measuring method.A detailed description of the various schemes of the drum water level control,the dynamic characteristics of the drum water level control objects are studied,analyzing the reasons of false water level;Among of the Single pulse,double pulse and three impulse control system,three impulse control system of single pulse and pulse control system,it is to control the quality is best,can effectively meet the requirements of speediness,stability,accuracy of the system,can effectively avoid the "false water level" phenomenon.The system adopts Siemens company S7-400H series of redundant PLC,programming and configuration using matched with the PCS7 programming software.Through the data acquisition and processing,the realization of the three impulse of drum level control,the interlock control and automatic protection function of drum water level control.Through the man-machine interface configuration software,the realization of system screen display,real-time monitoring,control parameter adjustment,historical trend of acquisition,alarm system and other functions.Finally,according to the control of CDQ boiler,simulation of the drum level control system by using MATLAB,the results show that fuzzy adaptive PID controller control system stronger adaptive ability,anti-interference ability and better robustness than the three impulse PID control system,can ensure the stability of water level.