The Research And Application Of Electric Boiler Temperature Control Algorithm

Electric heating boiler with its characteristic of environmental protection,high thermal efficiency, small volume, heating is convenient and so on, hasbecome the main heating equipment. To produce steam boiler equipment andcontrol the temperature in a certain range is the important measures to improvethe boiler safety and economy. Because the domestic electric boiler use startedrelatively late, so in the practical, the control algorithm is relatively simple andrough, the control mode is also boorish, so the automation control level is nothigh, makes the control effect is not good, the accuracy is not high, so finding anappropriate control scheme is a significant work. With the popularity ofcomputer application, computer and automatic control theory combining iswidely used in social fields. In the industrial control, computer control alsoreflected a lot advantages, it can realize all kinds of complicated controlalgorithm through the programming and greatly enhance the industrial controlautomation level.The design uses the existing boiler control system in the laboratory as anexample. In the computer, using RTW toolbox of Matlab/Simulink environmentrealizes the boiler temperature hardware-in-the-loop simulation. Firstestablishing communication links between the computer and other boilersperipheral hardware equipment through the I/O interface card, and using the stepresponse to establish the mathematical model of the temperature system, thenrespectively using four different control methods designs the system:conventional PID control, Dahlin control and PID-Dahlin section control andCMAC-Dahlin compound controller, realizes the Simulink simulation andsemi-physical real-time control, and then the control effect is analyzed andcompared. The conventional PID controller can make the temperature realizingbetter control by choosing proper control parameters, but the response time islong, and adjustment of control parameters is more complex, required to passthrough trial and error to find satisfactory parameter value. And because Dahlincontrol algorithm is limited by sampling time in the actual system, the control effect is not too ideal, emergence a static error and overstrike，But its responsespeed is faster than the PID, so we are looking for a segmented controlcombined the two kinds of control method, the experimental results show thatthe segmented control method combines the advantages of the two kinds ofcontroller, which can achieve good control effect. Finally, the CMAC neuralnetwork is used to adjust the output of Dahlin algorithm, to implement a newCMAC–Dahlin controller, this controller does not need parameter setting, canreduce the workload of staff design. The method controlling the temperature isto make the system response speed fast, no overstrike and no steady-state errorand so on.