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论文类型：期刊论文

发表时间：2013-01-01

发表刊物：COLD REGIONS SCIENCE AND TECHNOLOGY

收录刊物：SCIE、EI

卷号：85

页面范围：34-41

ISSN号：0165-232X

关键字：Effective thermal conductivity; Ice; Gas pore; Temperature; Thermokarst lake

摘要：Effective thermal conductivity (ETC) of thermokarst lake ice (TLI) is a key factor in simulating the ice processes in permafrost regions of Qinghai-Tibet Plateau (QTP). Typical TLI blocks sampled from central QTP were prepared to measure their ETC in vertical and horizontal directions at various temperatures. The ETC values of TLI are ranging between 1.60 and 2.10 W/(mK). The ETC values in both directions are very close, and change obviously along the ice depth. The ETC of TLI increases monotonously with decreasing ice temperature between 0 and 25 degrees C Both the theoretical modeling and experimental results demonstrate the effects of gas pore structures on ETC of TU. The temperature-averaged ETC decreases gradually as the porosity increases. A simple linear combination of two structural models is proposed for predicting the ETC against the porosity by introducing an empirical coefficient. This coefficient is controlled by the gas pore size, content, shape and configuration. (C) 2012 Elsevier B.V. All rights reserved.