Research On Scale Inhibition Characteristics Of Pipe Inner Wall Based On Swept Electromagnetic Field

The circulating cooling water system is widely used in electric power,metallurgy,petrochemical and other fields,and is an essential part of large-scale heat exchange equipment.However,as time goes by,the inner walls of the pipes of the circulating cooling water system will continue to generate calcium carbonate and other salt scales.The formation of scales will reduce the heat transfer efficiency of the heat exchange equipment,accelerate the aging of the equipment,and cause safety hazards.Therefore,the cooling water pipeline must be treated.The electromagnetic anti-scaling technology has the advantages of high anti-scaling efficiency,low energy consumption,safety and pollution-free,etc.,and its development prospects are very broad.Based on the circulating cooling water treatment technology,this article uses sweep frequency electromagnetic field to prevent and remove the scale of the circulating water pipeline,and analyzes the formation process of the scale on the inner wall of the circulating water pipeline and the factors affecting the scale of the circulating water pipeline.The anti-scaling mechanism of the sweep frequency electromagnetic field is summarized and analyzed,and the ANSYS electromagnetic field simulation software is used to study the influence of the number of coil turns,pipe material and pipe diameter on the intensity and distribution of the magnetic field in the processing chamber.Through comprehensive analysis,it can be obtained that the sweep frequency range and the intensity of the induced magnetic field are two important factors that affect the anti-scaling effect;it is most appropriate to choose a PVC pipe with a 100-turn winding coil and an inner diameter of100 mm as the simulated pipeline parameter.By studying the anti-scale mechanism of the sweep frequency electromagnetic field,a sweep frequency electromagnetic field descaling device is designed.The working principle of the sweep frequency electromagnetic field descaling device is: the single-chip microcomputer generates a square wave signal with a specific frequency,and the square wave signal is generated by a level conversion circuit.Boost to increase the load capacity,and then transform the square wave signal into a triangle wave signal through the integration circuit,the sweep frequency signal generation circuit converts the input triangle wave signal into a sweep frequency square wave signal through the CD4046 chip,and finally through the drive circuit and power amplifier circuit Amplify the power and drive the electromagnetic coil to generate a sweep frequency electromagnetic field to achieve the purpose of descaling.The frequency adjustable range of the descaling device is 20KHz-70 KHz.On the basis of the anti-scaling mechanism of the sweep frequency electromagnetic field and the descaling device designed in this paper,a static experiment system of the sweep frequency electromagnetic field anti-scaling and a constant temperature simulation circulating cooling water experiment system were built.It shows that: the aqueous solution treated by the frequency sweep electromagnetic field will accelerate the formation of calcium carbonate scale and the crystalline form of the scale is mainly aragonite,and its loose structure is easily carried away by the water flow instead of being deposited on the pipe wall;under the working conditions of this experiment,When the frequency sweep range is 50KHz-60 KHz,the conductivity and pH value of the simulated circulating cooling water solution have the largest drop,and the descaling rate and descaling efficiency are the highest.This frequency sweeping range is the best descaling frequency for the hard water.