摘要
结合地热能源桩现场试验,在桩身内部埋设应变/温度传感器,监测进/出口水温、桩身温度和轴向应变.分析不同间歇比下桩身轴向附加温度应力与桩侧附加摩阻力的变化规律,比较间歇与连续模式下地热能源桩的传热性能与热-力学特性.试验结果表明,间歇比对地热能源桩的短期传热性能影响比长期传热性能影响大.当间歇比为1、2时,性能系数平均值分别为3.95、4.00,桩身每延米换热量平均值分别为101.2、107.3 W/m.间歇比对桩身温度影响较明显,间歇比为1的桩身平均温度增量比间歇比为2的高66%.桩身中部的轴向观测应变大于桩两端的,桩身轴向附加温度应力和桩侧附加摩阻力均随间歇比的增大而减小.在桩身温度恢复阶段,间歇比为1、2工况的桩身温度,轴向观测应变和轴向附加温度应力均有残余.
Combined with the field test of geothermal energy pile,the strain/temperature sensors were embedded in the pile body to monitor the inlet/outlet water temperature,the temperature of the pile body and the axial strain.A variation law of the additional axial thermal stress and the additional frictional resistance of the pile under different intermittent ratios was analyzed,the heat transfer performance and thermo-mechanical properties of geothermal energy piles in intermittent and continuous modes were compared.Test results showed that the effect of intermittent ratio on short-term heat transfer performance of geothermal energy piles was greater than that on long-term heat transfer performance.When the intermittent ratio was 1 and 2,The average values of performance coefficient was 3.95 and 4.00,and the average heat transfer per meter of the pile body was 101.2 and 107.3 W/m,respectively.The intermittent ratio had a significant effect on the pile body temperature,and the average temperature increment of the pile body with the intermittent ration of 1 was 66%higher than that with the intermittent ration of 2.The axial observed strain in the middle of the pile body was greater than that at the two ends of the pile,and the additional axial thermal stress and the additional frictional resistance of the pile decreased with the increase of the intermittent ratio.During the recovery stage of pile temperature,the pile temperature,axial observed strain and additional axial thermal stress under intermittent ratio of 1 and 2 were all residual.
作者
刘春阳
方鹏飞
张日红
谢新宇
娄扬
张秋善
朱大勇
LIU Chun-yang;FANG Peng-fei;ZHANG Ri-hong;XIE Xin-yu;LOU Yang;ZHANG Qiu-shan;ZHU Da-yong(Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China;NingboTech University,Ningbo 315100,China;Ningbo Research Institute,Zhejiang University,Ningbo 315100,China;ZCONE High-Tech Pile Industry Holdings Limited Company,Ningbo 315145,China)
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2023年第3期562-572,共11页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(51708496)
浙江省自然科学基金资助项目(LY16E080010)
宁波市自然科学基金资助项目(2021J169).
关键词
间歇比
地热能源桩
多次温度循环
换热性能
热-力学响应
现场试验
intermittent ratio
geothermal energy pile
multiple temperature cycle
heat transfer performance
thermo-mechanical response
field test
