| Title |
Predicting the Effective Thermal Conductivity of Some Sand-Water Mixtures Used for Backfilling Materials of Ground Heat Exchanger |
| Keywords |
열전도도 ; 모래-물 혼합물 ; 지중열교환기 ; 뒤채움재 ; 비정상 탐침법 Thermal conductivity ; Sand-water mixture ; Ground heat exchanger ; Backfilling material ; Transient hot probe method |
| Abstract |
This paper presents the results of a laboratory study on the thermal conductivity of sand(silica, quartzite, limestone, sandstone, granite and two masonry sands)-water mixtures used for ground heat exchanger backfilling materials. Nearly 260 tests were performed in a thermal conductivity measuring system to characterize the relationships between the thermal conductivity of mixtures and the water content. The experimental results show that the thermal conductivity of mixtures increases with increasing dry density and with increasing water content. The most widely used empirical prediction models for thermal conductivity of soils were found inappropriate to estimate the thermal conductivity of unsaturated sandwater mixtures. An improved model using an exponential relationship to compute the thermal conductivity of dry sands and empirical relationship to assess the normalized thermal conductivity of unsaturated sand-water mixtures is presented. |