地下岩土热物性及地下水渗流速度确定

提出了可用于现场测量地下岩土的导热系数、容积比热容等热物性参数以及地下水渗流速度的方法．埋设在地下的地热换热器与周围岩土换热过程可以近似为无限大介质中移动线热源传热问题．该方法克服了其它模型对钻孔中埋管的具体位置、上升管和下降管之间的距离以及埋管和回填材料的物性等参数的要求，相应消除上述参数测量带来的误差．通过测量地下埋管的加热功率、循环水流量、出入口水温随时间变化，确定了某地源热泵空调系统工程地下岩土的热物性参数及地下水渗流速度，检验证实了该方法的实用性和可靠性．

Method for Determining Deep Ground Thermal Properties Accounting for Water Advection

A heat transfer model accounting for groundwater advection was proposed for determining the thermal conductivity and volumetric specific heat capacity of deep ground soil conveniently at worksites. The heat transfer between the buried geothermal heat exchanger and surrounding ground was considered as a moving line-source in an infinite medium. This model did not need exact information of the buried U-tube location, spacing between up and down tubes, the properties of the tubes and backfills, and other parameters in borehole as usual cases. A practical site test was conducted to obtain heat flux imposed on the buried loop, water flow rate, temperatures at the outlet and inlet of the loop by an in-situ measuring apparatus. The model, together with optimal estimation algorithm, was used to determine the thermal properties of the deep ground soil and groundwater advection velocity at the worksite.