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Abstract：
In this study, the influence of an axial-electromagnetic field treatment device (AEFTD) with a solenoid structure using different electromagnetic frequencies on calcium carbonate (CaCO3) crystallization fouling on the tube side of a shell-and-tube heat exchanger was investigated. The experimental results indicated that the application of the AEFTD could effectively reduce fouling resistance and decelerate the growth rate of CaCO3 fouling. The opposite trend between fouling resistance and the outlet temperature of an experimental fluid indicated that the application of the AEFTD could enhance heat transfer. Meanwhile, the crystal morphologies of the fouling samples were analyzed by means of scanning electron microscopy (SEM). The axial-electromagnetic field favored the formation of vaterite as opposed to calcite. Non-adhesive vaterite did not easily aggregate into clusters and was suspended in bulk to form muddy fouling that could be carried away by turbulent flow. Furthermore, the anti-fouling mechanism of the axial-electromagnetic field is discussed in detail. The anti-fouling effect of the AEFTD on CaCO3 fouling exhibited extreme characteristics in this study. Therefore, the effectiveness of the AEFTD is contingent upon the selection of the electromagnetic parameters.
摘要：
在这项研究中,研究了具有不同电磁频率的螺线管结构的轴向电磁场处理装置（AEFTD）对管壳式换热器管侧碳酸钙（CaCO3）结晶污垢的影响。实验结果表明，AEFTD的应用可以有效降低污垢阻力，减缓CaCO3污垢的生长速度。结垢阻力与实验流体出口温度之间的相反趋势表明，应用AEFTD可以增强传热。同时,通过扫描电子显微镜（SEM）分析了污垢样品的晶体形貌。与方解石相反，轴向电磁场有利于球陨石的形成。非粘性球特石不易聚集成簇，并大量悬浮形成泥状污垢，可被湍流带走。此外，详细讨论了轴向电磁场的防污机理。在这项研究中，AEFTD对CaCO3污垢的防污作用表现出极端的特征。因此,AEFTD的有效性取决于电磁参数的选择。
