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Thermal Conductivity Measurement of Grouting Materials for Ground Heat Exchanger Borehole  

Sohn, Byong-Hu (Fire & Engineering Services Research Department, KICT)
Shin, Hyun-Joon (Fire & Engineering Services Research Department, KICT)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.18, no.6, 2006 , pp. 493-500 More about this Journal
Abstract
This paper concerns the measurement of thermal conductivity of grouting materials for ground loop heat exchanger. A thermal conductivity meter, QTM-500 based on modified transient hot wire method was used to measure the thermal conductivity of neat bentonite and mixtures of bentonite and various additives. Relative to the total mixture mass, as the percent additive was increased the mixture thermal conductivity increased. For the bentonite-silica sand mixtures, the higher density of the sand particles resulted in much higher mixture thermal conductivity. The quartzite and silica sands produced the largest increases in mixture thermal conductivity, while common masonry and limestone sands produced lower thermal conductivity increases.
Keywords
Thermal conductivity; Grouting material; Bentonite; Additive; Ground heat exchanger; Borehole; Transient hot wire method;
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