Method to Estimate Thermal Conductivity of Subsurface Media

• Published in: Ground water monitoring & remediation Vol. 41; no. 1; pp. 99 - 105
• Main Authors: Karimi Askarani, Kayvan, Gallo, Sam, Kirkman, Andrew J., Sale, Tom C.
• Format: Journal Article
• Language: English
• Published: Malden, USA Wiley Periodicals, Inc 2021; Wiley Subscription Services, Inc
• Subjects: Computer applications; Exact solutions; Groundwater; Heat conductivity; Heat transfer; In situ temperature; Internet of Things; Moisture content; Petroleum; Petroleum refining; Refineries; Software; Soil; Soil water; Soils; Temperature data; Temperature sensors; Thermal conductivity; Water content
• ISSN: 1069-3629; 1745-6592
• DOI: 10.1111/gwmr.12419

Thermal conductivity is an essential parameter in heat transfer models including soil‐water systems. Herein, an Internet of Things (IoT) tool and a computational method are advanced for vertically resolving in situ thermal conductivity values in soil‐groundwater systems. A demonstrative application of this approach at a former petroleum refinery is presented. A line heat source is co‐located with a vertical string of in situ temperature sensors. Five‐minute multiple level temperature data were collected before, during, and after a 100‐min long heating period. Vertically distributed temperature data are transformed into vertically discretized thermal conductivity values using an analytical solution. Results fall in the range of thermal conductivity values reported in the literature. Specifically, estimated thermal conductivity values from 0.3 to 7.3 m below ground surface range between 0.7 and 5.4 (W/m/C) with the highest values occurring in media with greater water content. Overall, the advanced method in this study provides a pragmatic approach for vertically resolving subsurface thermal conductivity values applicable for many scientific disciplines.