电加热在土壤气相抽提(SVE)中的实验研究

Experimental Research for Electric Heating in Soil Vapor Extraction(SVE)

研究了固定热源对不同填料粒径、填料含水率升温的影响。以不同粒径干燥石英砂为填料进行的实验结果表明,砂粒粒径越小,达到的最高温度越高。对含水石英砂进行加热实验结果表明,上层石英砂的最终温度与干砂相似,下层石英砂的最高温度低于干砂。石英砂中的水分对热传递以及热扩散速度的影响显著,实验前期含水石英砂的升温速度高于干砂。实验还表明,接近热源的砂层温度远远超过水沸点,随着与热源距离的增加,砂层所能达到的最大温度在下降。

An experimental study has been carried out to find out the effect of temperature caused by fixed heat- ing element for different particle sizes and moisture contents on filling. Experiments of different particle sizes on dry quartz sands showed that smaller particle size of sand led to higher end temperature. Experiments of wet quartz sands indicated that the end temperature of upper sand was similar to dry sands ; the highest temperature in the low- er area was lower than the dry sand. Moisture in quartz sand has significant influence on heat transfer and thermal diffusion speed. The results of the experiment indicated that the sand that was nearby the heat source, which its temperature was much higher than water boiling point. With the increase of the distance from heat source, the sand that can be reached maximum temperature decreased.