Study On Electromagnetic Field Synergetic Treatment Scale Inhibition Experiment Of Circulating Cooling Water Of Power Plants And Mechanism

Based on the scale of circulating cooling water of power plant as the research object, using the dual channel industrial circulating cooling water test bench and integrated magnetoelectric equipment of anti-scaling treatment to study circulating cooling water of plant scale anti-scaling experiments and mechanism analysis, using scanning electron microscopy (SEM) observed calcite and aragonite morphology and the change of the grain size in the water; using X-ray diffractometer (XRD) determined crystal structure of the scale sample. by the diffraction data of sample to determined the scale of the crystal lattice parameters, discussed scale inhibition mechanism of electromagnetic field.This paper introduces the improving design of dual-channel industrial circulating cooling water analysis test bench, introduced selection of electromagnetic flowmeter and peristaltic pump and automatic control system of signal acquisition, etc. conducted a series of transformation in the original test bench, improved the test bench running stability and signal acquisition accuracy.Designed the four factors and four levels orthogonal experiment, using the test bench and the power plant circulating water treatment of anti-scaling do scale experiments, analyzing the scale inhibition rate of the orthogonal experiment results, the best conditions of laboratory scale parameter were circulating water flow velocity were0.870m/s, pulse frequency were100Hz, working voltage were voltage five thousand volts, Square wave duty ratio was70%. the experiment cycle were30h, under the condition of these parameters the scale inhibition rate of fouling resistance method rate was78.23%,the scale inhibition rate of weight method rate was63.14%, the method has good scale inhibition effect.Using scanning electron microscope and X-ray diffraction (XRD) analyzed scaling samples, by scanning electron microscope, getted the scale sample appearance characteristics of the experimental group and control group characteristics mainly about acicular and block,.by X-ray diffraction (XRD) analysis, getted the scale of the sample of all kinds of crystal phase, characteristic peaks, crystal parameters, and the information such as the percentage of each phase, the good scale inhibition effect set of untreatment group,the aragonite percentage composition was28.88%, and the calcite percentage composition was71.12%, on the contrary,in the treatment group,the aragonite percentage composition was78.99%and the calcite percentage composition is21.01%, after the processed of electromagnetic field, the percentage composition of aragonite is increased significantly and the calcite percentage composition obviously declined. Experiments found that the calcite contain huntite and aragonite do not contain huntite, the possible reason is that the Mg2+instead of Ca2+on the part of location under the impact of electromagnetic field, led to calcite gradually formed calcite and huntite mixture in the process of growth.Through the scale inhibition rate and grain size analysis, estimate the grain size of hard scale is larger, it is easy to deposit on pipe wall, caused scale inhibition rate low, the grain size of soft dirt is smaller, it is easy to washed away by water, getted higher scale inhibition rate.This paper mainly from the angle of the effect of the electromagnetic field of scale crystal scale inhibition mechanism to discuss the electromagnetic field is mainly affect stages of the CaCO3crystal growth, including crystal formation energy and growth of the crystal, explaining the change of scale crystal phase distribution in the circulating cooling water, electromagnetic fields can affect the gibbs free energy change, cause the change of surface energy and volume energy in the system, which affect the growth of crystal nucleus. the increase of electromagnetic field energy was conducive to formed metastable state CaCO3of higher energy,and restrained the formed steady-state CaCO3of lower energy.In this paper, from the perspective of cycle theory of (PBC) expounded the change of the the surface energy of the K, make the surface of K grow faster than the surface of F and S,formed the small grain size and the clusters of needle that like aragonite, and promote the growth of aragonite, inhibiting the form of calcite.