考虑到浅埋含水层渗透性高和热扩散能力强的特点,提出一种基于金属埋管的新型高效含水层换热技术,以实现地热能高效开发。通过室内模型试验研究金属埋管在不同渗透系数岩土材料中的换热特性以及温度响应特征。结果表明,加热功率恒定为80 W时,金属埋管的能效系数随岩土介质渗透系数的增大而增大,渗透系数为1.04×10-3 m/s的砾石能效系数较黏土提升72.31%,表明该技术在含水层具有极大的适用性。地温监测显示含水层渗透系数越大,其温度场温升速率越低,表明换热系统具有更好的换热可持续性。此外,加热功率对金属埋管能效系数影响较大,加热功率为100 W的换热器能效系数较50 W时提升73.08%,表明热激发对流换热效应在高负荷下更为显著。
Abstract
In order to overcome the drawbacks of low thermal efficiency and poor sustainable performance, this paper proposes a novel strategy using metal pipes and backfilling the borehole with permeable materials. The heat transfer process under different geo-materials and the soil temperature response are investigated through physical model tests. The results show that the energy efficiency coefficient （EEC） of a metal pipe increases with the increased permeability of the geo-materials. Compared with clay, the EEC of gravel with a hydraulic conductivity of 1.04×10-3 m/s increases by 72.31%, indicating the aquifer is a suitable geological setting for the application of the proposed technology. The monitoring of soil temperature display that the higher the hydraulic conductivity the slower the temperature change of the aquifer is, implying a higher thermal diffusion which in turn improves heat transfer efficiency. The EEC of the heat exchanger with a heating power of 100 W increases by 73.08% compared to 50 W, indicating the effects of thermally induced heat convection are more significant at a higher thermal load.
关键词
热交换器 /
渗透系数 /
地热能 /
传热
Key words
heat exchangers /
hydraulic conductivity /
geothermal energy /
heat transfer
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参考文献
[1] 韩再生, 冉伟彦, 佟红兵, 等. 浅层地热能勘查评价[J]. 中国地质, 2007, 34(6): 1115-1121.
HAN Z S, RAN W Y, TONG H B, et al.Exploration and evaluation of shallow geothermal energy[J]. Geology in China, 2007, 34(6): 1115-1121.
[2] 苏克敬. 推进《地下水管理条例》实施努力开创中国地下水依法治污新局面[J]. 中国环境监察, 2022, 70(1): 50-52.
SU K J.Promote the implementation of the Regulations on Groundwater Management and strive to create a new situation of groundwater pollution control according to the law in China[J]. China environment supervision, 2022, 70(1): 50-52.
[3] 邓军涛, 王娟娟, 郑建国. 不同管径和埋深地埋管换热器换热性能分析[J]. 太阳能学报, 2021, 42(9): 416-421.
DENG J T, WANG J J, ZHENG J G.Analysis on thermal performance of ground heat exchanger with various diameters and depths[J]. Acta energiae solaris sinica, 2021, 42(9): 416-421.
[4] 徐森森, 刘寅, 袁冬颜. 基于埋地换热器的强化传热研究现状及展望[J]. 流体机械, 2019, 47(6): 68-75.
XU S S, LIU Y, YUAN D Y.Research status and prospect of heat transfer enhancement based on ground heat exchanger[J]. Fluid machinery, 2019, 47(6): 68-75.
[5] 林瑞泰. 多孔介质传热传质引论[M]. 北京: 科学出版社, 1995.
LIN R T.Mass transfer and heat transfer in porous media[M]. Beijing: Science Press, 1995.
[6] BIDARMAGHZ A, NARSILIO G A.Shallow geothermal energy: emerging convective phenomena in permeable saturated soils[J]. Géotechnique letters, 2016, 6(2): 1-5.
[7] 范蕊, 马最良, 姚杨, 等. 地下水流动对地下埋管换热器影响的实验研究[J]. 太阳能学报, 2007, 28(8): 874-880.
FAN R, MA Z L, YAO Y, et al.Experimental research on influence of groundwater advection on performance of GHE[J]. Acta energiae solaris sinica, 2007, 28(8): 874-880.
[8] 张春一, 晋华, 刘虎, 等. 渗流对竖直地埋管换热器换热性能的影响[J]. 水电能源科学, 2015, 33(10): 108-111.
ZHANG C Y, JIN H, LIU H, et al.Influence of groundwater seepage on heat transfer performance of vertical geothermal heat exchangers[J]. Water resources and power, 2015, 33(10): 108-111.
[9] 刘逸, 陈培强. 地下水渗流对地埋管换热器换热的影响研究[J]. 制冷, 2019, 38(3): 10-16.
LIU Y, CHEN P Q.Study on influence of groundwater seepage on buried tube heat exchanger[J]. Refrigeration, 2019, 38(3): 10-16.
[10] GEHLIN S, HELLSTRM G.Influence on thermal response test by groundwater flow in vertical fractures in hard rock[J]. Renewable energy, 2003, 28(14): 2221-2238.
基金
国家自然科学基金（41877200）; 科技部地球深部钻探与深地资源开发国际联合研究中心（DEDRD-2022-06）
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