Please wait a minute...
浙江大学学报(工学版)
Journal of ZheJiang University (Engineering Science)  2022, Vol. 56 Issue (1): 144-151    DOI: 10.3785/j.issn.1008-973X.2022.01.016
    
Coupled water-vapor-heat transport simulation on in-situ thermal conduction heating remediation of soil
Xin-yu XU1(),Nan HU1,Li-wu FAN1,2,*()
1. Institute of Thermal Science and Power Systems, Zhejiang University, Hangzhou 310027, China
2. State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
Download: HTML     PDF(3946KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

Numerical simulations were performed using COMSOL Multiphysics to analyze the temperature rise in soil during the course of thermal conduction heating (TCH) remediation based on a coupled water-vapor-heat transport model in order to analyze the underground temporal and spatial temperature distributions during in-situ TCH remediation of organic compound-contaminated soil. The transient variations of the distributions of temperature, and water and vapor concentrations were predicted. The numerical results were validated by comparing with the existing experimental data obtained with a single TCH tube from field tests. Then the effects of soil porosity, water saturation, and capillarity on the temporal and spatial temperature distributions were analyzed by parametric analysis. Results show that the temperature rise rate becomes slower with higher porosity and water saturation, because more heat is used for the evaporation of water. Capillary force contributes to water migration. Then the evaporation rate is increased.

Key words： in-situ thermal remediation of soil      temporal and spatial temperature distribution      coupled water-vapor-heat transport      water saturation      soil porosity      capillarity     
Received: 20 January 2021      Published: 05 January 2022
CLC:  X 53  
Fund:  国家重点研发计划资助项目（2019YFC1805701）
Corresponding Authors: Li-wu FAN     E-mail: xuxinyu0228@zju.edu.cn;liwufan@zju.edu.cn
Service
E-mail this article
Add to my bookshelf
Add to citation manager
E-mail Alert
RSS
Articles by authors
Xin-yu XU
Nan HU
Li-wu FAN
Cite this article:

Xin-yu XU,Nan HU,Li-wu FAN. Coupled water-vapor-heat transport simulation on in-situ thermal conduction heating remediation of soil. Journal of ZheJiang University (Engineering Science), 2022, 56(1): 144-151.

URL:

https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2022.01.016     OR     https://www.zjujournals.com/eng/Y2022/V56/I1/144


土壤原位热传导修复水-汽-热耦合输运模拟

为了研究有机污染场地原位热传导热修复过程中地层温度的时空分布规律，基于典型场地建立水-汽-热耦合输运模型，通过COMSOL Multiphysics多物理场仿真平台对原位热传导修复过程中的土壤温升进行数值模拟研究，预测得到温度、水相及蒸汽相浓度分布随时间的变化规律. 利用文献中的单根加热棒加热场地实测数据对模拟结果进行对比验证，通过参数化分析探究土壤孔隙度、水饱和度及毛细作用力对土壤温度时空分布的影响. 结果表明，大孔隙度和水高饱和度将导致土壤温升减慢，这是由于大量热量用于液态水蒸发过程. 毛细管力会强化液态水输运，增大蒸发速率．


关键词： 土壤原位热修复,  温度时空分布,  水-汽-热耦合输运,  水饱和度,  土壤孔隙度,  毛细力 
Fig.1 Schematic diagram of thermal conduction heating (TCH) technology
Fig.2 Comparison and validation of temperature variation during heating process with single heating tube
Fig.3 Schematic diagram of in situ thermal remediation unit of soil
类别 ρ/(kg·m?3) cp/(J·kg?1·K?1) λ/(W·m?1·K?1) μ /(Pa·s)
土壤 2650 1750 1.41 —
水 998.2 4182 0.59 1.002×10-3
蒸汽 — 2062 0.026 1.8×10-5
干空气 1.205 1006 0.025 1.81×10-5
Tab.1 Thermophysical properties of parameters in numerical simulation
Fig.4 Isotherms at various time instants
Fig.5 Soil gas phase velocity distribution during heating process
Fig.6 Water and vapor distribution during heating process
Fig.7 Temperature variation during heating process with different porosity
Fig.8 Parameter variation during heating process with different porosity
Fig.9 Temperature variation during heating process with different water saturation
Fig.10 Parameter variation during heating process with different water saturation
Fig.11 Temperature variation during heating process with different capillary pressure
Fig.12 Parameter variation during heating process with different capillary pressure
[1]   骆永明, 滕应 中国土壤污染与修复科技研究进展和展望[J]. 土壤学报, 2020, 57 (5): 1137- 1142
LUO Yong-ming, TENG Ying Research progress and prospects on soil pollution and remediation in China[J]. Acta Pedologica Sinica, 2020, 57 (5): 1137- 1142
[2]   宋昕, 林娜, 殷鹏华 中国污染场地修复现状及产业前景分析[J]. 土壤, 2015, 47 (1): 1- 7
SONG Xin, LIN Na, YIN Peng-hua Contaminated site remediation industry in China: current state and future trends[J]. Soils, 2015, 47 (1): 1- 7
[3]   BASTON D P, FALTA R W, KUEPER B H Numerical modeling of thermal conductive heating in fractured bedrock[J]. Groundwater, 2010, 48 (6): 836- 843
doi: 10.1111/j.1745-6584.2010.00722.x
[4]   HERON G, LACHANCE J, BAKER R Removal of PCE DNAPL from tight clays using in situ thermal desorption[J]. Groundwater Monitoring and Remediation, 2013, 33 (4): 31- 43
doi: 10.1111/gwmr.12028
[5]   VIDONISH J E, ZYGOURAKIS K, MASIELLO C A, et al Thermal treatment of hydrocarbon-impacted soils: a review of technology innovation for sustainable remediation[J]. Engineering, 2016, 2 (4): 426- 437
doi: 10.1016/J.ENG.2016.04.005
[6]   HERON G, PARKER K, FOURNIER S, et al World’s largest in situ thermal desorption project: challenges and solutions[J]. Ground Water Monitoring and Remediation, 2015, 35 (3): 89- 100
doi: 10.1111/gwmr.12115
[7]   李书鹏, 焦文涛, 李鸿炫, 等 燃气热脱附技术修复有机污染场地研究与应用进展[J]. 环境工程学报, 2019, 13 (9): 2037- 2048
LI Shu-peng, JIAO Wen-tao, LI Hong-xuan, et al Research and application progress of gas thermal desorption technology for the remediation of organic contaminated sites[J]. Chinese Journal of Environmental Engineering, 2019, 13 (9): 2037- 2048
doi: 10.12030/j.cjee.201905108
[8]   迟克宇, 李传维, 籍龙杰, 等 原位电热脱附技术在某有机污染场地修复中的应用效果[J]. 环境工程学报, 2019, 13 (9): 2049- 2059
CHI Ke-yu, LI Chuan-wei, JI Long-jie, et al Application effect of in-situ electric thermal desorption technology used in remediation at an organics-contaminated site[J]. Chinese Journal of Environmental Engineering, 2019, 13 (9): 2049- 2059
doi: 10.12030/j.cjee.201905110
[9]   LACHANCE J, BAKER R S, GALLIGAN J P, et al. Application of “thermal conductive heating/in situ thermal desorption (ISTD)” to the remediation of chlorinated volatile organic compounds in saturated and unsaturated settings [C]// Proceedings of the 4th International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey: [s. n. ], 2004.
[10]   HERON G, ZUTPHEN M V, CHRISTENSEN T H, et al Soil heating for enhanced remediation of chlorinated solvents: a laboratory study on resistive heating and vapor extraction in a silty, low-permeable soil contaminated with trichloroethylene[J]. Environmental Science and Technology, 1998, 32 (10): 1474- 1481
doi: 10.1021/es970563j
[11]   张学良, 廖朋辉, 李群, 等 复杂有机物污染地块原位热脱附修复技术的研究[J]. 土壤通报, 2018, 49 (4): 993- 1000
ZHANG Xue-liang, LIAO Peng-hui, LI Qun, et al Remediation of complex organic compounds in contaminated plot with in-situ thermal desorption[J]. Chinese Journal of Soil Science, 2018, 49 (4): 993- 1000
[12]   YEUNG A T. Remediation technologies for contaminated sites [M]. Berlin: Springer, 2010: 328−369.
[13]   孙磊, 蒋新, 周健民, 等 五氯酚污染土壤的热修复初探[J]. 土壤学报, 2004, 41 (3): 462- 465
SUN Lei, JIANG Xin, ZHOU Jian-min, et al Preliminary study of the thermal remediation of pentachlorophenol contaminated soil[J]. Acta Pedologica Sinica, 2004, 41 (3): 462- 465
doi: 10.3321/j.issn:0564-3929.2004.03.021
[14]   王慧玲, 王峰, 张学平, 等 气相抽提法去除土壤中挥发性有机污染物现场试验研究[J]. 科学技术与工程, 2015, 15 (10): 238- 242
WANG Hui-ling, WANG Feng, ZHANG Xue-ping, et al Field study on influencing factors in removal of volatile organic compounds by soil vapor extraction[J]. Science Technology and Engineering, 2015, 15 (10): 238- 242
doi: 10.3969/j.issn.1671-1815.2015.10.048
[15]   XU H, LI Y, GAO L, et al Planned heating control strategy and thermodynamic modeling of a natural gas thermal desorption system for contaminated soil[J]. Energies, 2020, 13 (3): 642
doi: 10.3390/en13030642
[16]   陈永俊, 孙如华, 王翔, 等 基于COMSOL热强化SVE技术的污染场地数值模拟[J]. 环境工程, 2020, 38 (3): 174- 179
CHEN Yong-jun, SUN Ru-hua, WANG Xiang, et al Numerical simulation of polluted site based on COMSOL thermal enhancement SVE technology[J]. Environmental Engineering, 2020, 38 (3): 174- 179
[17]   LEBRON C, HERON G, KUEPER B, et al. Dense non aqueous phase liquid (DNAPL) removal from fractured rock using thermal conductive heating (TCH) [R]. Alexandria: Environmental Security Technology Certification Program, 2013: 10-13.
[18]   林瑞泰. 多孔介质传热传质引论[M]. 北京: 科学出版社, 1995.
[19]   PHILIP J R, DEVRIES D A Moisture movement in porous materials under temperature gradient[J]. Eos Transactions American Geophysical Union, 1957, 38 (2): 222- 232
doi: 10.1029/TR038i002p00222
[20]   WEN W, LAI Y, YOU Z Numerical modeling of water–heat–vapor–salt transport in unsaturated soil under evaporation[J]. International Journal of Heat and Mass Transfer, 2020, 159: 120114
doi: 10.1016/j.ijheatmasstransfer.2020.120114
[21]   HARTLEY J G. An analysis of the thermal stability of the soil environment of underground electrical cables [D]. Georgia: Georgia Institute of Technology, 1977.
[22]   邵明安, 王全九, 黄明斌. 土壤物理学[M]. 北京: 高等教育出版社, 2006.
[23]   籍龙杰, 刘鹏, 韦云霄, 等 单根加热管原位加热土壤过程中温度变化规律[J]. 环境工程, 2019, 37 (2): 165- 169
JI Long-jie, LIU Peng, WEI Yun-xiao, et al Research on temperature variation in soil during in-situ heating with single heating tube[J]. Environmental Engineering, 2019, 37 (2): 165- 169
[24]   WANG W, LI C, LI Y, et al Numerical analysis of heat transfer performance of in situ thermal remediation of large polluted soil areas[J]. Energies, 2019, 12 (24): 4622
doi: 10.3390/en12244622
[25]   张琳琳, 赵蕾, 杨柳 管群间歇散热的土壤温度响应与恢复特性[J]. 浙江大学学报: 工学版, 2016, 50 (2): 299- 305
ZHANG Lin-lin, ZHAO Lei, YANG Liu Soil temperature response and recovery characteristics of intermittent heat emission in multi-boreholes[J]. Journal of Zhejiang University: Engineering Science, 2016, 50 (2): 299- 305
[26]   杨荣贵, 雷树业, 杜建华 突发高温下多孔介质的热质迁移模拟[J]. 清华大学学报: 自然科学版, 1999, 39 (6): 79- 83
YANG Rong-gui, LEI Shu-ye, DU Jian-hua Simulation of heat and mass transfer in porous media at burst high temperature[J]. Journal of Tsinghua University: Science and Technology, 1999, 39 (6): 79- 83
[27]   卢涛. 毛细多孔介质干燥过程中传热传质模型研究及应用[D]. 大连: 大连理工大学, 2003.
LU Tao. Study and application of model for heat and mass transfer in capillary porous media during drying [D]. Dalian: Dalian University of Technology, 2003.
[1] Qian CHEN,Wu CAI,Jie CHEN,Hu-biao ZHAO,Chang-xin LI,Yun-feng HE. Degradation effects of different chemical oxidants on polycyclic aromatic hydrocarbons in soil[J]. Journal of ZheJiang University (Engineering Science), 2019, 53(12): 2437-2444.