Study On Optimization Of A Coal Gasification Control System

After exhaustive investigation about current coal gasification control systems, this thesis developed a decentralized control system (DCS) to control a bed-fixed and batched coal gasification process on the basement of the ECS-100 DCS equipped by Zhejiang Supcon Technology Co. LTD. During the realization of the system, the optimal characteristics of universality, the modulization and the intelligence of the system are highly mentioned.6 months of real stable running of this system has already brought quite great benefit to the corporation where the author is employed.The most important task in coal gasification is to fulfill the control process. The procedure of the coal gasification is normally fixed and circulatory, the strategy correctness of controlling a single furnace is therefore the key point to insure the whole coal gasification. Under the develop environment of ECS-100, the realized single furnace control system can tune the parameters of the controller without necessity of considering the function stage of the furnace by using the so called three parameters (real parameters, interim parameters and pre-setup parameters) tuning method. An overall scheme of the single furnace control system has been given by integrating the modules like parameters management, phase estimation and valve position output, etc.By means of some optimized strategies such as pointer evaluation, multi-wind queue and so on, an optimal and harmonically cooperated multi-furnace control scheme is designed based on single furnace control techniques. The control program is also successfully developed. In the design of the consecutive control system of the coal gasification, the one loop digital PID tuner offered by ECS-100 is adopted to satisfy indices demands of the system with zero static error and perfect transient performance.The optimal and stable proportion of hydrogen to nitrogen in the process of coal gasification is very difficult to achieve because of the large time lag, the strong disturbance, the big parametric quantity and the model uncertainty of the system. Through utilization of a kind of simple exponent function, that is served as the objective function, a prediction function model controller (PFC) contrived in this thesis has obtained a series of excellent control effects, for example, sufficient stable margin and satisfied transient characteristics.