Research On The Automatic Control Of Thermal Electrical Device

Transforming the 75t/h CFBB (circulating fluidized bed boiler) of Yan’an Oil Refinery into the Thermoelectric Polygeneration Device is one of the critical projects of technological improvement and environmental protection, which needs a proper method to control the boiler of the system. This thesis compared three industrial tuning methods, which are reaction curve method, attenuation curve method and critical proportional band method, to draw forth an intelligent optimal PID tunning method which is based on specified gain and phase margin. The simulation shows that this tunning method ensures the closed loop system have a strong robust performence and can be used to optimize the PID parameters of the boiler in the Thermoelectric Polygeneration Device. However, the optimized PID parameters still can’t meet the ideal expection in practical use because of the nonlinerity, strong time variation and lengthy lag performence of the CFBB, which draw forth the method of summarizing the practical experience and establishing the rulebase. Practice shows that a good result is achieved in the use of the method, which make it possible to control the burning of 75/h CFBB.