Research Of Boiler Drum Water Level Automatic Control System Based On Fuzzy Neural Network

The boiler is indispensable power equipment in the process of industrial automation. It is very important to ensure the safe and stable production of the boiler automatic control. Water level of steam drum reflects the balance between the steam and water flow rate in the boiler, which is a very important to operate the monitoring date of boiler.And at present what is mainly used is the conwentional PID algorithmin the process control, whose control effect is not ideal, so it is great practical significance to study and improve a new control algorithm.First,according to the working principle of boiler which analyzes the dynamic and static characteristics of the boiler liquid level. On the certain assumptions that we can write out the material balance equation and the energy banlance equation by the way of the mechanism modeling and make some operations andchanges, in order to get the transfer function of the steam flow and water flow from the boiler and establish the basic mathematicalmodel of the steam drum water level. Secondly comparing with the advantages and disadvantages of the single pulse,double pulse, three impules control scheme of the boiler steam drun water level,three impulse control system is chosen as the steam drum water level control system through analysis. And in detail we elaborate the advantages and disadvantages of the traditional PID control algorithm, fuzzy control algorithm and fuzzy neural network control algorithm. On this basis,we propose a fuzzy neural network control scheme based on Mamdani model, which makes full use of the power of expression that the fuzzy system is easy to be understood and the strong ability to learn quickly of neural network, the two methods of intelligent fuses in together and mutual complement each other, thus which they improve the expression ability and the strong ability to learn quickly of the system, we hope the control system gets more effective control and achieves a good control effect to the boiler which has the nonlinearity and large time delay. Finally taking MATLAB as simulation software, using SIMULINK module respectively sets up three impulse control system of the steam drum water level which is based on PID control algorithm under the condition of the stabilization and undisturbed of the simulation about the steam flow and the feed water flow, the control performance of three main control algorithms to carry on the quantitative analysis and comparison. The results show that the neural network control system of boiler drum water level control can be satisfied the needs in the scope of the technology allows requirements such as the the shortest setting time, less overshoot and strong anti-interference capability. Experimental simulation and analysis results show that the control algorithm of fuzzy neural network really can realize the adjustment to the system of the boilers’ water level in feasible and superior way.