深层地热利用中对井水热运移规律及其分析模型和方法研究

In recent years,energy crisis and environment deterioration are impelling the mankind to exploit and utilize renewable energy sources.Geothermal energy is a kind of clean and renewable energy. Its exploitation and utilization has attracted much attention. Whereas the amount of geothermal energy in shallow depth is still limited, vast amount of geothermal energy is available at greater depths. However, for the exploitation of geothermal energy at great depth, research on some fundamental as well as technical problems is required.This research proposal is intended to conduct fundamentalstudy on doublet system for geothermal energy exploitation.Comprehensive studies will be first made on the achieved results both home and abroad. Based on that, numerical model and analysis method will be studied for the analysis of the heat and water transfer in the system through theoretical and experimental investigations, taking some doublet systems constructed in Beijing, especially that operational on the campus of Tsinghua University as target problems. Numerical models and calculation method will be proposed which can describe the heat and water transfer through fractured rock properly, and at the same time can perform multiscale analysis of practical projects. The proposed model and methods will be applied to doublet systems and even geothermal reservoirs in order to reveal its work mechanism. It is believed that this research will provide both theoretical as well as technical support for the optimal design and management of doublet system for geothermal exploitation.

当今世界范围内的能源危机、环境恶化迫使人们寻求可再生能源的开发利用。地热能是一种清洁环保的可再生能源，其开发利用已受到普遍重视。然而浅层地热能毕竟有限，深层地热利用潜力巨大，但其中有不少基础理论和技术问题需要研究。本项目针对深层地热利用中的对井系统进行基础研究，拟在全面深入梳理国内外已有研究成果的基础上，依托北京已建成的一些地热对井，特别是申请者所在大学校园内已投入使用、深度达3000余米的地热对井，通过深入的理论及试验实测分析，研究地热对井系统水热运移的数值分析模型和方法，提出既能够较准确描述裂隙岩体渗流传热特点，又能进行多尺度分析的数值模拟方法，并将其应用于对井系统和实际地热田的模拟分析。进而深入揭示裂隙岩体中水岩传热的机理，揭示地热对井运行的规律，从而为地热对井乃至更大规模的地热田开采方案的优化设计与运营维护提供依据，为地热利用的健康发展在理论和分析方法方面提供支撑。

地热对井系统是深层地热开采利用的一种主要方式。本项目针对深地热对井系统进行基础研究，通过深入调研已有对井运行状况及理论分析、试验实测和数值模拟，在数值分析模型及方法、地热层水岩传热机理及对井运行规律两方面取得不同创新程度的研究成果，包括基岩裂隙渗流传热模型和模拟裂隙-岩石基质换热过程的裂隙渗流传热单元，裂隙岩体中渗流-热传导耦合分析的等效连续化模型,无限域渗流、热传导分析的几种局部人工边界，实际地热对井的示踪剂试验以及依据实测数据反分析评价地热对井运行状态的方法等。针对所提出的计算方法均开发了相应的计算程序模块，可以实现在相关软件平台的计算分析。所取得的主要成果均以学术论文形式在国内外一流期刊及学术会议发表，得到国内外同行的肯定和重视。这些成果可为地热对井的优化设计与运营维护在理论分析及评估方法方面提供支撑，也为进一步的研究提供重要参考。