上海地区岩土体分层导热特征及其计算模式研究

Study on characters and calculation mode of layered thermal conductivity of soil mass in Shanghai

由于不同土层、不同岩性的导热系数存在差异,分层导热系数的精准计算利于地埋管换热器优化设计,提高地热利用率,降低地源热泵系统长期运行造成的岩土体热不平衡。热响应测试得到的导热系数较为准确,然无法体现岩土体的分层特性。室内测试法获取的导热系数能够体现岩土体的分层特性,但不够准确。本研究结合上海地区地下岩土体的分层特征,将地下岩土体分层细化、岩性归类,结合室内测试和现场测试结果,利用权重系数法建立岩土体分层导热系数与综合导热系数的相关关系,得到的导热系数更能反映地下岩土体分层特征也更精确。

Due to the difference in thermal conductivity between different soil layers and lithologies,the accurate calculation of layered thermal conductivity is beneficial to the optimization design of ground heat exchangers,improving the geothermal utilization rate,and reducing the geothermal thermal imbalance caused by the long-term operation of ground source heat pump systems.The thermal conductivity obtained by the thermal response test is more accurate,but it does not reflect the stratification characteristics of the rock and soil.The thermal conductivity obtained by the indoor test method can reflect the stratification characteristics of the rock and soil,but it is not accurate enough.This study combines the stratification characteristics of underground rock and soil in Shanghai,a stratified and lithological classification of underground rock and soil,along with indoor test and field test results,using the weight coefficient method to establish the layered thermal conductivity of rock and soil.According to the correlation of the thermal conductivity,the thermal conductivity obtained can better reflect the stratification characteristics of the underground rock and soil and be more accurate.