Study On Crystal Analysis Of Scale Of Power Plant Circulating Cooling Water And Mechanism Of Scale Inhibition

Firstly, this study improves " two-channel industrial circulating cooling water test bench" data acquisition system, so that the experimental platform has many functions such as automatic operation and water replenishing and data acquisition. "Magneto-electric collaborative industrial circulating cooling water scale inhibition treatment device" is designed, and it enables electric and magnetic fields synergism to support circulating cooling water, thus improving the efficiency of electromagnetic energy transfer.Secondly, "two-channel industrial circulating cooling water test bench" and " device of magnetoelectric coordinated treatment of industrial circulating cooling water anti-scaling" three-factor and four-level orthogonal scale inhibition experiment helps to select the experimental parameters. After the operation period of 24h, with 300 turns of coil and pulse voltage of 20V, the best scale inhibition parameters are determined that circulation flow velocity is 0.669m/s, pulse frequency is 50Hz, voltage is 6.0kV, the inhibition rate with fouling resistance law is 68.95%, and the inhibition rate with heat exchanger tubes weight is 66.36%, thus significant inhibition effect is realized.The scale crystal experiences scanning electron microscopy (SEM) and X ray diffraction (XRD) analysis, and the results show that, after processing by high voltage electrostatic field and frequency pulse magnetic field, the calcite content in calcium carbonate crystals, the main components of scale, reduces in different degrees, and the aragonite content increases at different degree. For example, in the orthogonal test 13 #, the aragonite content in un-treatment group is 78.76% aragonite, and the calcite content is 21.24%, while the aragonite content in treatment group is 100%, and the calcite content is 0%, which means that electromagnetic field can inhibit the formation of calcite and promote formation of aragonite.Finally, from perspective of the activation of water molecules, the influence mechanism of high voltage electrostatic field and variable-frequency pulsed magnetic field’ inhibiting on the circulating cooling water. The electric field and magnetic field transmitted to water can, on one hand, its increase water molecular mobility; on the other hand, when the pulse frequency is close to that of the water molecule, the "resonance" with water molecules is increased, followed by increased activation degree. The activated water molecules can enhance ion hydration of Ca+ water (H2O) and CO32-(H2O), to realize scale inhibition.As for the growth of scale crystal, after applying high voltage electrostatic field and frequency pulse magnetic field, free energy in the system increases, causing more probability to form aragonite nucleation. Aragonite belongs to the orthorhombic system, and its structure is layered graphite sample, thus it is easily washed with the flow of water followed by reduced deposition on the heat transfer surface, to realize scale inhibition effect.