冷介质通过井筒注入某地质结构的流动与传热预测软件研发

Software development of flow and heat transfer prediction of a cold medium injected into a geological structure through wellbore

中文关键词: 冷介质  冷量损失  井筒  传热

英文关键词: cold medium  loss of cooling capacity  wellbore  heat transfer

中文摘要:

      通过井筒向某地质结构内注入冷介质时，由于地温与冷介质之间存在温差，冷介质将通过井筒结构与土壤进行热量交换，最终导致冷介质冷量损失进而温度升高而达不到所需温度要求。因此，在施工前，需要对井筒进行冷量损失和沿井筒的温度分布的预测，为保冷结构设计以及井筒结构材料选型提供数据支持。由于注入冷介质的过程中，热量交换过程是一个非稳态传热过程，通常只能采用数值模拟来进行预测。为了简化数值模拟复杂的计算过程，采用准稳态的传热方法来构建单相冷介质通过井筒注入时的流动换热的物理数学模型，并开发了一个数值仿真软件。将仿真结果同商业软件FLUENT模拟结果进行了比较，表明温度分布和冷量损失基本一致，由此验证了所提模型的正确性和可靠性，为非工程热物理专业的工程技术人员提供能够预测低温工质在井筒流动与换热过程的仿真软件。

英文摘要:

      When a cold medium is injected into a geologic structure through a wellbore, there is heat transfer between the cold medium and soil via the wellbore due to the presence of temperature difference between the cold medium and the soil, which leads to loss of cooling capacity and under-required temperature. So it is necessary to make the wellbore insulated and predict the value of cooling capacity loss as well as the temperature distribution along the wellbore. Since the heat exchange process of the injection process is an unsteady state, only numerical simulation can be used to predict the heat transfer process. To simplify the numerical simulation process, a quasi-steady state was adopted to construct physical and mathematic model to describe flow and heat transfer of a single phase cold medium through a wellbore. A predicting software is developed. The results obtained by the software were compared with the ones obtained by the commercial software FLUENT. It was found the temperature distribution and cooling capacity loss were consistent, which indicate that the proposed model is reliable. This developed predicting software can predict the flow and heat transfer of low temperature medium through a wellbore for those non thermophysics engineers.