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http://dx.doi.org/10.12652/Ksce.2013.33.6.2381

Thermal Behavior of Energy Pile Considering Ground Thermal Conductivity and Thermal Interference Between Piles  

Go, Gyu Hyun (KAIST)
Yoon, Seok (KAIST)
Park, Do Won (KAIST)
Lee, Seung-Rae (KAIST)
Publication Information
KSCE Journal of Civil and Environmental Engineering Research / v.33, no.6, 2013 , pp. 2381-2391 More about this Journal
Abstract
In general, ground's thermal properties, types of heat exchanger, operational method, thermal interference between piles can be considered as key factors which affect the thermal performance of energy pile. This study focused on the effect of these factors on the performance by a numerical model reflecting a real ground condition. Depending on the degree of saturation of ground, pile's heat transfer rate showed a maximum difference of three times, and the thermal resistance of pile made a maximum difference of 8.7%. As for the type of heat exchanger effects on thermal performance, thermal efficiency of 3U type energy pile had a higher value than those of W and U types. The periodic operation (8 hours operation, 16 hours pause) can preserve about 20% of heat efficiency compared to continuous operation, and hence it has an advantage of preventing the thermal accumulation phenomenon. Thermal interference effect in group piles may vary depending on the ground condition because the extent decreases as the ground condition varies from saturated to dry. The optimal separation distance that maintains the decreasing rate of heat efficiency less than 1% was suggested as 3.2D in U type, 3.6D in W type, and 3.7D in 3U type in a general ground condition.
Keywords
Energy pile; Thermal performance analysis; Saturation; Thermal interference; Operating evaluation;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
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