Fuzzy Control System Of Ulatrasonic Anti-scaling And Descaling Device Based On PLC

With the progress of technology and the constantly improving requirements in energy-saving and environmental protection in recent years,high-efficiency,non-corrosive,safe and environmentally friendly ultrasonic cleaning technology has gradually become popular.The ultrasonic pulse anti-scaling and descaling device has become one of the important areas in industrial cleaning research and commercial application.Currently,the existing ultrasonic pulse anti-scaling and descaling device is usually controlled with open-loop control method,which requires manual intervention to complete,taking long time,bringing man-made risk and causing low efficiency.What’s more,the ultrasonic device system runs independently with data acquisition system and there is no network interaction.In this dissertation,the continuously matured and improved fuzzy control technology is introduced into the ultrasonic scale removal and prevention system of heat exchanger,based on PLC.Through adjusting the parameters and automatic judgment of the stability of the ultrasonic scale removal and prevention system,the purposes,including improving the operation efficiency of the device,are realized.In the system designed in this dissertation,temperature transmitter,pressure sensor and electromagnetic flowmeter are used to collect temperature,pressure and flow data.According to the data of temperature,pressure and flow,PLC calculates the heat transfer coefficient in real time,and calculates the error of heat transfer coefficient.Fuzzy controller in PLC divides the error of heat transfer coefficient into five fuzzy subsets,and fuzzily process it according to the fuzzy membership function,then uses Mamdani model for fuzzy reasoning to complete the fuzzy decision.Finally,fuzzy controller resolves ambiguity according to mean value of maximum(MOMM)ant get the working frequency of the system.Based on the calculation result of the fuzzy controller,the PLC completes the control of the ultrasonic descaling and anti-scaling device.The experiment shows that the heat transfer coefficient of the device changes greatly before and after the installation of the fuzzy control system,and the effect has been improved obviously.By adopting the fuzzy control system,the heat transfer coefficient shows an upward trend and meets the performance requirements.Therefore,fuzzy control system plays a very important role in anti-scaling and descaling,high-efficiency heat exchange,sterilization and algae killing,energy saving,pollution reduction,prolonging the service life of equipment and so on,and achieves the purpose of improving the performance of the system.