대한설비공학회:학술대회논문집 (Proceedings of the SAREK Conference)
- 대한설비공학회 2007년도 동계학술발표대회 논문집
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- Pages.429-433
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- 2007
지열냉난방시스템 수직형 지중열교환기 그라우트의 열적 특성에 관한 연구
A Study on Thermal Conductivity Properties of Ground Heat Exchangers for GSHP systems
- 발행 : 2007.11.30
초록
Cement mortar and concrete can be used as grouts but problems regarding shrinkage and the discord of coefficients of thermal expansion between grouts and HDPE pipes has to be solved. Thermal conductivities of wet condition two times larger than those of dry condition, except for pure cement mortar. The addition of sand into the cement grouts greatly increases the thermal conductivity. The addition of bentonite into the cement grouts reduces thermal conductivity thus reducing the density. Bentonite grouting must be used only below the groundwater table since bentonite grouts possesses high shrinkage property in dry condition. The addition of sand prevents the shrinkage of bentonite grouts. Bentonite manufactured in Korea can be used since they possess similar thermal conductivities with imported products. The addition of sand into the bentonite grouts greatly increases the thermal conductivity.
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