Current practice of underground artificial ground freezing (AGF) typically involves huge refrigeration systems of large economic and environmental costs. In this study, a novel AGF technique is proposed deploying available cold wind in cold regions. This is achieved by a static heat transfer device called thermosyphon equipped with an air insulation layer. A refrigeration unit can be optionally integrated to meet additional cooling requirements. The introduction of air insulation isolates the thermosyphon from ground zones where freezing is not needed, resulting in: (1) steering the cooling resources (cold wind or refrigeration) towards zones of interest; and (2) minimizing refrigeration load. This design is demonstrated using well-validated mathematical models from our previous work based on two-phase enthalpy method of the ground coupled with a thermal resistance network for the thermosyphon. Two Canadian mines are considered: the Cigar Lake Mine and the Giant Mine. The results show that our proposed design can speed the freezing time by 30% at the Giant Mine and by two months at the Cigar Lake Mine. Further, a cooling load of 2.4 GWh can be saved at the Cigar Lake Mine. Overall, this study provides mining practitioners with sustainable solutions of underground AGF.

中文翻译：

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利用空气隔热热虹吸管对寒冷地区地下矿井进行人工地面冻结


当前地下人工地面冻结（AGF）的实践通常涉及巨大的制冷系统，造成巨大的经济和环境成本。在这项研究中，提出了一种新颖的 AGF 技术，在寒冷地区部署可用的冷风。这是通过配备有空气绝缘层的称为热虹吸管的静态传热装置来实现的。可以选择集成制冷装置以满足额外的冷却要求。空气绝缘的引入将热虹吸管与不需要冷冻的地面区域隔离，从而导致：（1）将冷却资源（冷风或制冷）引导至感兴趣的区域； (2) 最大限度地减少制冷负荷。该设计使用我们之前的工作中经过充分验证的数学模型进行了演示，该数学模型基于地面的两相焓法以及热虹吸管的热阻网络。考虑了加拿大的两个矿场：雪茄湖矿场和巨型矿场。结果表明，我们提出的设计可以将巨人矿的冻结时间缩短 30%，将雪茄湖矿的冻结时间缩短两个月。此外，雪茄湖矿还可节省 2.4 GWh 的冷负荷。总的来说，这项研究为采矿从业者提供了地下 AGF 的可持续解决方案。