Soil thermal conductivity prediction for district heating pre-insulated pipeline in operation

► Heat loss from pre-insulated district heating (DH) pipes in operation were analyzed. ► Prediction of soil thermal conductivity (λs) over time and space was presented. ► Method is based on measured (Θexp) vs. simulated (Θsim) soil temperature comparison. ► Predicted λs was defined by the solution of function λs = f(Θsim − Θexp) at Θsim − Θexp =0. ► λs prediction could enable more accurate determination of heat loss in DH system.