A study of soil thermal conductivity measurement based on the actively heated distributed temperature sensing cable
-
摘要:
主动加热型分布式温度感测技术（AH-DTS）可通过植入土体中的光缆实现不同层位土体导热系数的分布式连续测量，但AH-DTS光缆导热系数测量方法的准确性和敏感性有待进一步研究。通过室内试验，对比了碳纤维加热感测光缆（CFHC）和铜网加热感测光缆（CMHC）的热响应过程，通过数值模拟验证了光缆结构对导热系数测量结果的影响。研究结果表明：（1）CFHC和CMHC的热响应过程可通过微分法分为光缆内部传热、纤-土过渡以及土体稳定传热3个阶段，光缆结构差异导致传热速率不同，使得CFHC导热系数测量初始时刻比CMHC提前100 s；（2）光缆尺寸与比热容差异下CFHC的升温值更高，相同测温精度CFHC的导热系数测量结果较CMHC更加稳定准确；（3）增大加热功率或延长加热时间均会提高CFHC和CMHC测量土体导热系数的准确性。研究成果为该技术的进一步完善和推广提供了重要依据。
Abstract:The actively heated distributed temperature sensing technology (AH-DTS) can realize distributed continuous measurement of the soil thermal conductivity in different layers through optical cables implanted in the soil. However, the accuracy and sensitivity of soil thermal conductivity measurement by AH-DTS method need to be further studied. Through designing indoor tests with the loess, the aim of this study is to compare the thermal response process and the soil thermal conductivity measured by carbon fiber heated cable (CFHC) and copper-mesh heated cable (CMHC) under different heating strategies. The numerical simulation is used to furtherly verify the influence of the optical cable structure on the thermal conductivity measurement results. The results show that the thermal response process of CFHC and CMHC can be divided into three stages: Internal heat transfer of optical cable, fiber-soil transition and stable heat transfer of soil. The difference in optical cable structure will lead to different heat transfer rates, which makes the initial time of thermal conductivity measurement of CFHC 100 s earlier than that of CMHC. The temperature rise value of CFHC is higher under the difference of optical cable size and specific heat capacity. The thermal conductivity measurement result of CFHC is more stable and accurate than CMHC under the same DTS temperature measurement accuracy. Increasing the heating power or increasing the heating time will improve the accuracy of the soil thermal conductivity measurement by CFHC and CMHC. The research results provide an important basis for further improvement and promotion of this technology.
-
-
表 1 黄土的基本物理参数
Table 1. Basic physical parameters of the test soil
参数 原位含水率 塑限 液限 塑性指数 测量值 20.29% 17% 27% 10 
下载: 导出CSV
表 2 不同加热功率Q下CMHC的ΔT-lnt曲线拟合结果
Table 2. ΔT-lnt fitted results of CMHC under different heating power
Q
/（W·m−1）k R2 λ
/（W·m−1·K−1）相对误差
/（W·m−1·K−1）5 0.4012 0.9741 0.9917 −0.2523 10 0.6690 0.9775 1.1895 −0.0545 15 1.0092 0.9827 1.1828 −0.0612 20 1.3598 0.9939 1.1704 −0.0736 25 1.6210 0.9987 1.2273 −0.0167
下载: 导出CSV
-
[1] 夏才初,曹诗定,王伟. 能源地下工程的概念、应用与前景展望[J]. 地下空间与工程学报,2009,5(3):419 − 424. [XIA Caichu,CAO Shiding,WANG Wei. An introduction to energy geotechnical engineering[J]. Chinese Journal of Underground Space and Engineering,2009,5(3):419 − 424. (in Chinese with English abstract) doi: 10.3969/j.issn.1673-0836.2009.03.002
[2] 周殷康,阎长虹,郑军,等. 双孔隙压实膨润土的细观导热模型[J]. 岩土工程学报,2021,43(7):1352 − 1359. [ZHOU Yinkang,YAN Changhong,ZHENG Jun,et al. Mesoscale model for thermal conductivity of compacted dual-porosity bentonite[J]. Chinese Journal of Geotechnical Engineering,2021,43(7):1352 − 1359. (in Chinese with English abstract)
[3] 于明志,彭晓峰,方肇洪. 用于现场测量深层岩土导热系数的简化方法[J]. 热能动力工程,2003,18(5):512 − 514. [YU Mingzhi,PENG Xiaofeng,FANG Zhaohong. A simplified method for on-site measurement of the thermal conductivity of deep-layer rock soil[J]. Journal of Engineering for Thermal Energy and Power,2003,18(5):512 − 514. (in Chinese with English abstract) doi: 10.3969/j.issn.1001-2060.2003.05.019
[4] BOURNE-WEEB P J,AMATYA B L,SOGA K. A framework for understanding energy pile behavior[J]. ICE Proceedings of Geotechnical Engineering,2012,166(2):170 − 177.
[5] AMATYA B L,SOGA K,BOURNE-WEBB P J,et al. Thermo-mechanical behaviour of energy piles[J]. Géotechnique,2012,62(6):503 − 519.
[6] 唐盼盼,徐洁,卢永洪. 含水率及温度影响非饱和土导热系数的试验研究[J]. 防灾减灾工程学报,2019,39(4):678 − 683. [TANG Panpan,XU Jie,LU Yonghong. Experimental study on effects of water content and temperature on thermal conductivity of unsaturated soils[J]. Journal of Disaster Prevention and Mitigation Engineering,2019,39(4):678 − 683. (in Chinese with English abstract) doi: 10.13409/j.cnki.jdpme.2019.04.020
[7] MILUN S,KILIC T,BEGO O. Measurement of soil thermal properties by spherical probe[J]. IEEE Transactions on Instrumentation and Measurement,2005,54(3):1219 − 1226. doi: 10.1109/TIM.2005.847223
[8] 程文龙,马然,宋嘉梁. 基于随机近似热探针方法的土壤热物性高精度测量系统[J]. 流体机械,2013,41(8):63 − 66. [CHENG Wenlong,MA Ran,SONG Jialiang. Measurement apparatus of soil thermal properties by stochastic approximation thermal probe method with high accuracy[J]. Fluid Machinery,2013,41(8):63 − 66. (in Chinese with English abstract) doi: 10.3969/j.issn.1005-0329.2013.08.014
[9] ACUA J,PALM B. Distributed thermal response tests on pipe-in-pipe borehole heat exchangers[J]. Applied Energy,2013,109:312 − 320. doi: 10.1016/j.apenergy.2013.01.024
[10] SPITLER J D,GEHLIN S E A. Thermal response testing for ground source heat pump systems—An historical review[J]. Renewable and Sustainable Energy Reviews,2015,50:1125 − 1137. doi: 10.1016/j.rser.2015.05.061
[11] 桑宏伟,张春光,刘洋,等. 基于DTS的土体分布式导热系数测试方法[J]. 地下空间与工程学报,2020,16(2):540 − 546. [SANG Hongwei,ZHANG Chunguang,LIU Yang,et al. Testing method of distributed thermal conductivity of soil based on DTS[J]. Chinese Journal of Underground Space and Engineering,2020,16(2):540 − 546. (in Chinese with English abstract)
[12] XU Yunshan,ZENG Zhaotian,SUN Dean,et al. Comparative study on thermal properties of undisturbed and compacted lateritic soils subjected to drying and wetting[J]. Engineering Geology,2020,277:105800. doi: 10.1016/j.enggeo.2020.105800
[13] MOGENSEN P. Fluid to duct wall heat transfer in duct system heat storages[C]//Proceedings of The International Conference on Subsurface Heat Storage in Theory and Practice. Sweden: Swedish Council for Building Research, 1983: 652-657.
[14] 郭红仙,孟嘉伟,祝振南. 能源隧道热响应试验数值分析与适用性评价[J]. 防灾减灾工程学报,2019,39(4):572 − 578. [GUO Hongxian,MENG Jiawei,ZHU Zhennan. Numerical analysis and applicability evaluation of thermal response test in energy tunnels[J]. Journal of Disaster Prevention and Mitigation Engineering,2019,39(4):572 − 578. (in Chinese with English abstract) doi: 10.13409/j.cnki.jdpme.2019.04.005
[15] 肖衡林,蔡德所,何俊. 基于分布式光纤传感技术的岩土体导热系数测定方法[J]. 岩石力学与工程学报,2009,28(4):819 − 826. [XIAO Henglin,CAI Desuo,HE Jun. Measuring method of geomaterial thermal conductivity based on distributed optical fiber sensing technology[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(4):819 − 826. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2009.04.022
[16] 海那尔·别克吐尔逊,施斌,曹鼎峰,等. 基于DTS技术的多层土有效导热系数测量方法[J]. 防灾减灾工程学报,2018,38(2):282 − 288. [HAINAR Bieketuerxun,SHI Bin,CAO Dingfeng,et al. Effective thermal conductivity measurement for multilayered soil using DTS technology[J]. Journal of Disaster Prevention and Mitigation Engineering,2018,38(2):282 − 288. (in Chinese with English abstract) doi: 10.13409/j.cnki.jdpme.2018.02.011
[17] SOURBEER J J,LOHEIDE S P I. Obstacles to long-term soil moisture monitoring with heated distributed temperature sensing[J]. Hydrological Processes,2016,30(7):1017 − 1035. doi: 10.1002/hyp.10615
[18] 程伟, 孙梦雅, 徐洪兵, 等. 基于AHFO-FBG的黄土含水率不同率定方法对比分析[J/OL]. 工程地质学报. （2021-06-22）[2021-08-08]. https://doi.org/10.13544/j.cnki.jeg.2021-0037.
CHENG Wei, SUN Mengya, XU Hongbing, et al. Comparative analysis of different measuring methods of loess moisture content based on AHFO-FBG method[J/OL]. Journal of Engineering Geology.（2021-06-22）[2021-08-08].（in Chinese with English abstract）
[19] 曹鼎峰,施斌,顾凯,等. 土的含水率AHFO法测量中分段函数模型建立[J]. 水文地质工程地质,2016,43(6):41 − 47. [CAO Dingfeng,SHI Bin,GU Kai,et al. Establishment of the piecewise function model in the process of soil moisture monitoring with the AHFO method[J]. Hydrogeology & Engineering Geology,2016,43(6):41 − 47. (in Chinese with English abstract) doi: 10.16030/j.cnki.issn.1000-3665.2016.06.07
[20] 胡优,李敏,任姮烨,等. 基于加热光纤分布式温度传感器的土壤含水率测定方法[J]. 农业工程学报,2019,35(10):42 − 49. [HU You,LI Min,REN Hengye,et al. Measurement of soil water content using distributed temperature sensor with heated fiber optics[J]. Transactions of the Chinese Society of Agricultural Engineering,2019,35(10):42 − 49. (in Chinese with English abstract) doi: 10.11975/j.issn.1002-6819.2019.10.006
[21] SIMON N,BOUR O,LAVENANT N,et al. Numerical and experimental validation of the applicability of active-DTS experiments to estimate thermal conductivity and groundwater flux in porous media[J]. Water Resources Research,2021,57(1):1 − 27.
[22] SAYDE C,GREGORY C,GIL-RODRIGUEZ M,et al. Feasibility of soil moisture monitoring with heated fiber optics[J]. Water Resources Research,2010,46(6):2840 − 2849.
[23] STRIEGL A M,LOHEIDE S P I. Heated distributed temperature sensing for field scale soil moisture monitoring[J]. Groundwater,2012,50(3):340 − 347. doi: 10.1111/j.1745-6584.2012.00928.x
[24] BENSE V F,READ T,BOUR O,et al. Distributed temperature sensing as a downhole tool in hydrogeology[J]. Water Resources Research,2016,52(12):9259 − 9273. doi: 10.1002/2016WR018869
[25] CAO Dingfeng,SHI Bin,ZHU Honghu,et al. A distributed measurement method for in–situ soil moisture content by using carbon–fiber heated cable[J]. Journal of Rock Mechanics and Geotechnical Engineering,2015,7(6):700 − 707. doi: 10.1016/j.jrmge.2015.08.003
[26] ZHANG Bo,GU Kai,SHI Bin,et al. Actively heated fiber optics based thermal response test:A field demonstration[J]. Renewable and Sustainable Energy Reviews,2020,134:110336. doi: 10.1016/j.rser.2020.110336
[27] HAUSNER M B,SUÁREZ F,GLANDER K E,et al. Calibrating single-ended fiber-optic Raman spectra distributed temperature sensing data[J]. Sensors,2011,11(11):10859 − 10879. doi: 10.3390/s111110859
[28] INGERSOLL L R,PLASS H J. Theory of the ground pipe heat source for the heat pump[J]. ASHVE Transactions,1948,47:339 − 348.
[29] CIOCCA F,LUNATI I,VAN DE GIESEN N,et al. Heated optical fiber for distributed soil-moisture measurements:A lysimeter experiment[J]. Vadose Zone Journal,2012,11(4):1 − 10.
[30] 郭君仪,孙梦雅,施斌,等. 不同环境温度下土体含水率主动加热光纤法监测试验研究[J]. 岩土力学,2020,41(12):4137 − 4144. [GUO Junyi,SUN Mengya,SHI Bin,et al. Experimental study of water content in soils monitored with active heated fiber optic method at different ambient temperatures[J]. Rock and Soil Mechanics,2020,41(12):4137 − 4144. (in Chinese with English abstract) doi: 10.16285/j.rsm.2020.0516
[31] BENÍTEZ-BUELGA J,RODRÍGUEZ-SINOBAS L,SÁNCHEZ CALVO R,et al. Calibration of soil moisture sensing with subsurface heated fiber optics using numerical simulation[J]. Water Resources Research,2016,52(4):2985 − 2995. doi: 10.1002/2015WR017897
[32] SUN Mengya,SHI Bin,ZHANG Dan,et al. Study on calibration model of soil water content based on actively heated fiber-optic FBG method in the in-situ test[J]. Measurement,2020,165:108176. doi: 10.1016/j.measurement.2020.108176
[33] 刘洁,孙梦雅,施斌,等. 基于主动加热型FBG的土体干密度原位测量方法研究[J]. 岩土工程学报,2021,43(2):390 − 396. [LIU Jie,SUN Mengya,SHI Bin,et al. Feasibility study on actively heated FBG methods for dry density measurement[J]. Chinese Journal of Geotechnical Engineering,2021,43(2):390 − 396. (in Chinese with English abstract)
-
图(10)
表(2)
计量
- 文章访问数: 2288
- PDF下载数: 83
- 施引文献: 0