U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或...U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或ILS模型的G函数,考虑或忽略钻孔壁热流随时间变化,分别简称为ICS-q,ILS-q,ICS-c,ILS-c模型。通过与较为准确的二维数值模型及实验数据在2种边界条件下的对比,分析了这4种模型的准确性。结果表明:ILS-q模型在整体上最为准确,而ICS-q模型在分析UDBHE长期性能时最为准确;4种模型在前期均存在较大误差,但在足够长时间后,除了ILS-c和ICS-c模型在入口温度边界下仍有较大误差外,其他模型的误差均较小。研究结果可为UDBHE传热模型研究提供参考。展开更多
The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao...The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao,North China,and Zhangzhou basins are of special interest due to their considerable exploration depths,extensive development history,and high levels of research activity.This study focuses on the three basins to analyze their thermal reservoir characteristics in eastern China.Between 2017 and 2023,the research team carried out a comprehensive analysis involving deep boreholes that exceeded 4000 m in depth within these three basins.They meticulously created detailed physical profiles that captured essential characteristics such as porosity,permeability,and thermal properties,reaching down to the basement of each basin.The findings indicated that variations in thermal conductivity within shallow geotechnical layers significantly influence the redistribution of deep thermal energy in the upper layers of the earth.Furthermore,differences in physical properties notably affect heat transport processes.The research proposes distinct heat models tailored for each basin:For the Songliao Basin,a low-permeability model with homogeneous thermal properties is constructed;for the North China Basin,high permeability and thermal conductivity layers are highlighted;and a fracture network controlling water and heat is presented in the Zhangzhou Basin.To elucidate the thermal structure of these basins,the Curie surface and Moho surface were analyzed.The shallow Curie surface indicates ongoing intense thermal activity stemming from crustal heat sources,while a shallow Moho surface signifies historical vigorous mantle thermal activity associated with mantle source heat production.Furthermore,the research evaluates the geothermal resources and the potential for carbon emission reduction in these basins.Total volume of exploitable geothermal fluid is estimated to be 76.9×10^(9) m^(3)/a,corresponding to an annual renewable geothermal energy 1.47×10^(16)k J.The implementation of geothermal energy could lead to a reduction in annual CO_(2)emissions by nearly 2×10^(9) t,which constitutes about 17.4%of China’s national carbon emissions in 2022.This estimation provides invaluable theoretical insights and data support for geothermal exploration and sustainable development in eastern China.展开更多
文摘U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或ILS模型的G函数,考虑或忽略钻孔壁热流随时间变化,分别简称为ICS-q,ILS-q,ICS-c,ILS-c模型。通过与较为准确的二维数值模型及实验数据在2种边界条件下的对比,分析了这4种模型的准确性。结果表明:ILS-q模型在整体上最为准确,而ICS-q模型在分析UDBHE长期性能时最为准确;4种模型在前期均存在较大误差,但在足够长时间后,除了ILS-c和ICS-c模型在入口温度边界下仍有较大误差外,其他模型的误差均较小。研究结果可为UDBHE传热模型研究提供参考。
基金funded by the Basic Scientific Research of China Geological Academy(YK202305)National Key R&D Program of China(2019YFB1504101)+1 种基金National Natural Science Foundation of China(41602271)China Geological Survey(DD20160207 and DD20189112)。
文摘The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao,North China,and Zhangzhou basins are of special interest due to their considerable exploration depths,extensive development history,and high levels of research activity.This study focuses on the three basins to analyze their thermal reservoir characteristics in eastern China.Between 2017 and 2023,the research team carried out a comprehensive analysis involving deep boreholes that exceeded 4000 m in depth within these three basins.They meticulously created detailed physical profiles that captured essential characteristics such as porosity,permeability,and thermal properties,reaching down to the basement of each basin.The findings indicated that variations in thermal conductivity within shallow geotechnical layers significantly influence the redistribution of deep thermal energy in the upper layers of the earth.Furthermore,differences in physical properties notably affect heat transport processes.The research proposes distinct heat models tailored for each basin:For the Songliao Basin,a low-permeability model with homogeneous thermal properties is constructed;for the North China Basin,high permeability and thermal conductivity layers are highlighted;and a fracture network controlling water and heat is presented in the Zhangzhou Basin.To elucidate the thermal structure of these basins,the Curie surface and Moho surface were analyzed.The shallow Curie surface indicates ongoing intense thermal activity stemming from crustal heat sources,while a shallow Moho surface signifies historical vigorous mantle thermal activity associated with mantle source heat production.Furthermore,the research evaluates the geothermal resources and the potential for carbon emission reduction in these basins.Total volume of exploitable geothermal fluid is estimated to be 76.9×10^(9) m^(3)/a,corresponding to an annual renewable geothermal energy 1.47×10^(16)k J.The implementation of geothermal energy could lead to a reduction in annual CO_(2)emissions by nearly 2×10^(9) t,which constitutes about 17.4%of China’s national carbon emissions in 2022.This estimation provides invaluable theoretical insights and data support for geothermal exploration and sustainable development in eastern China.
