A METHOD TO CALCULATE SOIL'S THERMAL PROPERTIES FOR THE GROUND SOURCE HEAT PUMP SYSTEM

The soil's thermal properties around the single borehole have become the premise and foundation of the design and research of ground source heat pump system. This paper developed a new method to calculate soil's thermal diffusivity with lack of the backfill material's thermal conductivity in the single borehole based on the line source model. An experiment in situ was conducted to measure soil's thermal conductivity for applying ground source heat pump system. The results were used here to verify the new developed method. The heat conductivity coefficient was measured as 1.46W/m.K. and the thermal diffusivity coefficient was 0.729x10(-6)m(2)/s with the backfill material's thermal conductivity available; while the thermal diffusivity coefficient was 0.633 x10(-6)m(2)/s by the new method. The results showed that new developed method can be used in engineering projects especially for those being lack of backfill material's properties.