The Transient Method Measurements of Thermophysical Properties of Non-solid Clay Loam

The In the frame of extending the renewable energy systems, the use of the shallow geological bedrock below the houses is used for the seasonal heat storage purposes. Thus, the knowledge of the thermophysical properties of the soft clay loam materials present in the bedrock is important. On the basis of the known thermal diffusivity, thermal conductivity and specific heat of the materials around the energetic needle, one can calculate the time dependency of the heat dissipated and transferred into the surrounding. This allows calculating the temperature maps that can specify in more detail the heat penetration depth during the seasonal storage and pumping out of the heat accumulated during the year seasons. The aim is to optimize the efficiency of the system. The clay loams in the free nature contain high level of the moisture and thus have high values of specific heat. The pulse transient method was used to get the thermophysical parameters of these materials. Specimens were drilled out from the bedrock at depths 50, 150 and 250cm from the surface. The measured values of equilibrium sorption moisture show that obtained materials are very different. In the paper we show the possible influence of the redistribution of water content during the shooting of the heat pulse. The water redistribution deforms the temperature response. This effect was avoided by lowering the heat pulse power to minimal values that still allows the evaluation of the measurement.