A SINGLE PROBE TRANSIENT MOVING LINE SOURCE METHOD FOR DETERMINING THERMAL CONDUCTIVITY, THERMAL DIFFUSIVITY, AND SUPERFICIAL FLOW VELOCITY OF A POROUS MATERIAL WITH FLOW

摘要

This paper presents a method to determine the effective thermal conductivity and thermal diffusivity of a porous material, as well as the superficial flow velocity of fluid flowing through the porous matrix using a single probe transient moving line source method. The method transforms the transient analytical solution for a moving line source using differentiation to produce three independent equations to solve for the three unknowns. Empirical data are presented from a laboratory scale test apparatus for three test cases with known properties and flow rates to validate the method. The method is then applied to field data from a standing column well used in ground source heat pump systems to obtain the thermal and flow properties of the ground formation. The properties are inserted into the transient analytical solution for a moving line source and superimposed over the empirical data showing agreement between the model and the data. The method is more accurate than traditional methods for estimating thermal properties when flow conditions are present, and the implementation of the method does not require any additional thermal data.