关键词: 交叉缩放椭圆管, 纳米粒子, 结垢, 胶体, 污垢特性

Abstract: In order to study fouling of magnesium oxide nano-particles in alternating elliptical axis tube，magnesium oxide nano-particles were used to prepare colloidal solution as the study object. According to particulate size，particle concentration，liquid velocity and temperature，several groups of experiments were perfomed in the alternating elliptical axis tube. Scanning electron microscope was used to observe the fouling surface of the heat exchanger. The results show that particulate fouling of the alternating elliptical axis tube had no apparent induction period. Under the same conditions，the smaller the particulate size，the greater the fouling rate and asymptotic value of fouling resistance. The fouling rate and asymptotic value of fouling resistance increased with increasing particle concentration and decreased with increasing flow rate. The higher the inlet temperature，the smaller the asymptotic value of fouling resistance.

Key words: alternating elliptical axis tube, nanoparticles, fouling, colloid, fouling characteristics