井下流体抽注强制对流作用下超长重力热管地热系统取热强化增产研究  

Research on Heat Extraction Enhancement and Increased Production of Super-Long Gravity Heat Pipe Geothermal System Under Forced Convection of Downhole Fluid Withdrawal

作　　者：孙弘韬 黄文博[2,3,4] 刘鲲鹏 王翠华 陈娟雯[2,3,4] 郭剑 蒋方明[2,3,4] SUN Hongtao;HUANG Wenbo;LIU Kunpeng;WANG Cuihua;CHEN Juanwen;GUO Jian;JIANG Fangming(School of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China;Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;CAS Key Laboratory of Renewable Energy,Guangzhou 510640,China;Guangdong Provincial Key Laboratory of Renewable Energy,Guangzhou 510640,China;Tongji University,Shanghai 200092,China)

机构地区：[1]沈阳化工大学机械与动力工程学院,沈阳110142 [2]中国科学院广州能源研究所,广州510640 [3]中国科学院可再生能源重点实验室,广州510640 [4]广东省可再生能源重点实验室,广州510640 [5]同济大学,上海200092

出　　处：《新能源进展》2024年第5期588-596,共9页Advances in New and Renewable Energy

基　　金：国家重点研发计划项目(2021YFB1507300,2021YFB1507302);国家自然科学基金青年基金项目(52206287,52206126);江苏省科技项目(BE2022012);江阴市科技创新专项资金项目(JY0604A021015210001PB)。

摘　　要：采用超长重力热管开采深部地热资源能够有效避免增强型地热系统存在的工质损耗、结垢腐蚀以及地下连通困难等问题,但重力热管地热系统取热速率受限于热储的低导热率。提出一种井下流体抽注强制对流换热方案,对井下热管与热储之间流体流动传热过程进行数值模拟,获取了流场和温度场的变化规律,对比了井下流体静止和流动情况的采热性能,分析了不同质量流量、抽注时间比、周期时长对采热性能的影响。结果表明:井内抽注流动可以显著增强热管系统的采热性能,增大抽注流量能够提高采热率;慢抽快注的方式对采热率有明显的提升效果,抽注时间比越大采热性能越好;采热总时长不变,抽注周期时长越大对采热性能提升效果越明显。Utilizing super long gravity heat pipe to extract deep geothermal resources can effectively mitigate some common issues such as working fluid loss,fouling corrosion,and difficulties in underground connection that exist in enhanced geothermal systems.However,the heat transfer rate of the gravity heat pipe geothermal system is constrained by the low thermal conductivity of the reservoir.This study proposes a forced convective heat transfer scheme involving downhole fluid extraction and injection numerical simulation of fluid flow and heat transfer process between underground heat pipe and heat reservoir.Changes in the flow and temperature fields are obtained,and a comparison is made between the heat extraction performance of stationary and flowing downhole fluids.The impacts of different mass flow rates,extraction-to-injection time ratios,and cycle durations on heat extraction performance are examined.The results indicate that downhole fluid extraction and injection can significantly improve the system's heat extraction performance.Increasing the extraction flow rate of fluid leads to further improvement of the heat extraction rate.The strategy of slow extraction and rapid injection shows a notable enhancement effect in heat transfer rate,where a larger extraction-to-injection time ratio corresponds to better heat extraction performance.Moreover,while maintaining the total heat extraction time constant,prolonging the extraction cycle duration leads to a more pronounced improvement in heat extraction performance.

关 键 词：重力热管 强制对流 采热率 数值模拟 

分 类 号：TK52[动力工程及工程热物理—热能工程]