Experimental research on heat transfer characteristics and temperature rise law of in situ thermal remediation of soil

Abstract

With the advancement of industrialization, soil pollution has become a global environmental problem. In situ soil thermal remediation technology has attracted attention due to its wide application range, simultaneous removal of multiple pollutants and short time-consuming characteristics. In this study, using the principle of scale-down test, the law of temperature rise of the in situ thermal remediation of soil was experimentally studied; the heating construction period of the in situ soil remediation technology engineering application was predicted. The change law of temperature curve in different periods of soil heating is obtained. The results show that the soil temperature changes in three stages. Concentrated heating section: the temperature rises from the ambient temperature to the boiling point of water. Evaporation section: the water evaporates and the temperature maintains the boiling point temperature. Superheat section: the soil temperature continues to rise; the effect of heating power, water content and groundwater flow on heat transfer is studied. The results show that increasing the heating power, reducing the water content and preventing the seepage of surrounding water are all beneficial to the soil heating process. The research results provide favorable theoretical support for the laws of soil temperature rise, and the effect of heat transfer characteristics, simultaneously, provides a certain reference for actual soil remediation prediction, which is of great significance to the development of on-site soil thermal remediation technology.