螺旋槽管的污垢特性及其防垢性能实验研究(英文)

CHARACTERISTICS OF FOULING IN SPIRALLY INDENTED AND EXPERIMENTAL INVESTIGATION OF FOULING PREVENTION

通过实验测定了螺旋槽管内的结垢情况,并与光滑管进行了比较.实验中定时测定了螺旋槽管和光滑管的传热阻力,分别描绘了螺旋槽管和光滑管的结垢曲线.实验结果显示轧槽管的污垢热阻约为光滑管的0.52-0.88倍.与光滑管相比,螺旋槽管具有较低的污垢热阻,且热阻与时间的关系能够用污垢曲线模型具有蕴育期来解释.实验结果显示螺旋槽管的污垢渐近线值约为光滑管的52%-70%,并且污垢热阻随着流速增大显著减小,螺旋槽管的污垢热阻是流速的强函数.当其它参数不变,流速从0.25 m/s增大到0.75 m/s时,污垢热阻减小到原来的66.7%.努塞尔特准数值约为光滑管的1.8倍.

Experiment is conducted to show the fouling of spirally indented tube, which is compared with the fouling of smooth tube. The heat resistance of fouling in both tube is measured during a certain period. The fouling curves tested in spirally indented tube and smooth tube are described respectively. Experimental investigation shows that the heat resistance of fouling in corrugated tube is 0. 52-0. 88 times that of smooth tube. Compared with smooth tube, spirally indented tube has lower fouling-resistance and the heat resistance coming along with time can be demonstrated by fouling curve model having incubation period. In the experiment, fouling asymptote of spirally indented tube is 52%-70% that Of smooth tube. It is also seen that the heat resistance decreases obviously as the fluid velocity increases. The heat resistance of fouling in spirally indented tube is majorant of fluid velocity. When other parameter values are the same. the fluid velocity increases from 0.25 m/s to 0. 75 m/s, the heat resistance of fouling will reduce to 66. 7 %. The Nuselh criterion number is 1.8 times that of smooth tube.