基于土壤三组分重构模型的导热系数研究
|
摘要
土壤导热系数是土壤温差发电系统设计和优化等研究过程中最基本的参数,其具体数值常受到多种因素的影响。本研究的目的是建立能够有效预测不同因素下土壤导热系数的模型。在结合土壤自身多孔介质特性和固液气三相组成的基础上,构建土壤三组分随机混合重构模型,提出一种根据土壤干密度和质量含水率来计算土壤有效导热系数的方法。同时利用Hot Disk热常数分析仪实际测量32个不同含水率、不同干密度土壤样本的导热系数,对新建立的导热系数预测模型进行了测试验证。结果表明,本文提出的导热系数预测结果平均误差为3.05%,最大误差为10.82%;利用预测模型与前人研究实验值进行对比,平均误差为10.31%,最大误差为19.26%。结果证明该模型能较好地预测土壤导热系数。结合预测模型研究了土壤导热系数的影响因素,得到导热系数与干密度和质量含水率呈明显的正相关关系;并发现土壤在冻结状态下,导热性能明显增强。
Thermal conductivity of soil is the most basic parameter in the design and optimization of thermoelectric power generation system based on soil temperature differences, and there are many factors that could influence thermal conductivity. The purpose of this study is to establish a model that can effectively predict the soil thermal conductivity. Based on the characteristics of soil porous media and the three-phase composition, a reconstructing model of three randomly combined components was established and a method of calculating the effective thermal conductivity with the dry density and mass moisture content of soil was obtained. The Hot Disk thermal constant analyzer was used to measure thermal conductivity of 32 soil samples with different moisture contents and dry densities, and the newly established thermal conductivity prediction model was tested and verified. The results showed that the average error of the thermal conductivity prediction results was 3.05% and the maximum error was 10.82%. The average error of the prediction model was 10.31% and the maximum error was 19.26%, compared with the previous experimental data. The results proved that the calculation model can predict thermal conductivity effectively. Combined with the prediction model, the factors of soil thermal conductivity were studied, and the positive correlation between thermal conductivity and dry density or water content was found. And it was also found that the thermal conductivity of soil in the frozen state was significantly enhanced.
Thermal conductivity of soil is the most basic parameter in the design and optimization of thermoelectric power generation system based on soil temperature differences, and there are many factors that could influence thermal conductivity. The purpose of this study is to establish a model that can effectively predict the soil thermal conductivity. Based on the characteristics of soil porous media and the three-phase composition, a reconstructing model of three randomly combined components was established and a method of calculating the effective thermal conductivity with the dry density and mass moisture content of soil was obtained. The Hot Disk thermal constant analyzer was used to measure thermal conductivity of 32 soil samples with different moisture contents and dry densities, and the newly established thermal conductivity prediction model was tested and verified. The results showed that the average error of the thermal conductivity prediction results was 3.05% and the maximum error was 10.82%. The average error of the prediction model was 10.31% and the maximum error was 19.26%, compared with the previous experimental data. The results proved that the calculation model can predict thermal conductivity effectively. Combined with the prediction model, the factors of soil thermal conductivity were studied, and the positive correlation between thermal conductivity and dry density or water content was found. And it was also found that the thermal conductivity of soil in the frozen state was significantly enhanced.
引文
[1]Zhang Z, Li W, Kan J. Behavior of a thermoelectric power generation device based on solar irradiation and the earth’s surface-air temperature difference[J]. Energy Conversion and Management, 2015, 97(9):178-187.
[2]吴金卓,马琳,林文树.生物质发电技术和经济性研究综述[J].森林工程, 2012, 28(5):102-106.Wu J Z, Ma L, Lin W S. Literature review on biomass power generation technology and economic feasibility[J]. Journal of Forest Engineering, 2012, 28(5):102-106.
[3]侯立臣,顾鹂鸣,赵振伟,等.生物质能源林采伐机械化系统与装备发展探讨[J].林业机械与木工设备,2016,44(1):10-12.Hou L C,Gu L M,Zhao Z W,et al.Discussion on development of harvesting mechanization system and equipment for biomass energyforest[J].ForestryMachinery&Woodworking Equipment,2016,44(1):10-12.
[4]WangN,XuD,LiW,etal.Feasibilitystudyofanew thermoelectric conversion device utilizing the temperature differences in forest soi[lJ]. Acta Technica CSAV(Ceskoslovensk Akademie Ved), 2017, 62(1):1-12.
[5]张虎元,张学超,陈晓宁.不同遗址土的热物理参数研究[J].岩土力学, 2014, 35(1):58-62.Zhang H Y, Zhang X C, ChenX N. Research on thermal parameters of different earthen monument soils[J]. Rock and Soil Mechanics, 2014, 35(1):58-62.
[6]李海洋,胡海清,孙龙.我国森林可燃物含水率气象和土壤因子关系模型研究[J].森林工程, 2016, 32(3):1-6.Li H Y, Hu H Q, Sun L. Research on relational models of moisture content of dead forest fuel with meteorological factors and soil factors in China[J]. Journal of Forest Engineering, 2016, 32(3):1-6.
[7]李佳,周祖昊,王浩,等.土壤冻融过程中的多层水热耦合模拟研究[J].水文, 2016, 36(1):1-7.Li J, Zhou Z H, Wang H, et al. Study on simulation of water and heat transfer in soil freezing and thawing[J]. Journal of China Hydrology, 2016, 36(1):1-7.
[8]林梦磊,胡进娣,李爽,等.便携式土壤探测仪的研究[J].森林工程, 2017, 33(5):56-61.Lin M L, Hu J D, Li S, et al. Research of portable forest soil detector[J]. Journal of Forest Engineering, 2017, 33(5):56-61.
[9]肖琳,李晓超,赵晓豹,等.含水量与孔隙率对土体热导率影响的室内实验[J].解放军理工大学学报(自然科学版),2008, 9(3):241-247.Xiao L, Li X C, Zhao X B, et al. Laboratory on influences of moisture content and porosity thermal conductivity of soils[J].Journal of PLA University of Science and Technology, 2008,9(3):241-247.
[10]许欢欢.沥青混凝土面层压实后的孔隙率检测标准研究[J].公路工程,2016,41(4):184-187.Xu H H. Study on the porosity test standard for asphalt concrete surface compaction[J]. Highway Engineering, 2016, 41(4):184-187.
[11]隋晓凤,于明志,彭晓峰.含湿沙导热系数的测试与实验研究[J].热科学与技术, 2009, 8(1):20-24.Sui X F, Yu M Z, Peng X F. Experimental study on thermal conductivity measurement of wet sands[J]. Journal Thermal Science and Technology, 2009, 8(1):20-24.
[12]张海峰.含湿土壤的热物理性质研究[J].太阳能学报,2006, 27(10):1069-1072.Zhang H F. Investigation of the thermal properties of wet porous soils[J]. Acta Energiae Solars Sinica, 2006,27(10):1069-1072.
[13]HanJ,SunQ,XingH,etal.Experimentalstudyon thermophysical properties of clay after high temperature[J].Applied Thermal Engineering, 2017, 111(2):847-854.
[14]Goodhew S, Griffiths R. Analysis of thermal-probe measurements using an iterative method to give sample conductivity and diffusivity data[J]. Applied Energy, 2004, 77(2):205-223.
[15]Putkonen J. Determination of frozen soil thermal properties by heated needle probe[J]. Permafrost and Periglacial Processes,2003, 14(4):343-347.
[16]相方园.土壤孔隙网络模型的程序设计与实现[J].湖北农业科学, 2009, 48(4):974-977.XiangFY.Designandrealizationfornetworkmodel reconstruction of soil pore[J]. Hubei Agricultural Sciences,2009, 48(4):974-977.
[17]王强,戴景民,何小瓦.基于HotDisk方法测量热导率的影响因素[J].天津大学学报, 2009, 42(1):970-974.Wang Q, Dai J M, He X W. Influence factors analysis thermal conductivity measurement with HotDisk technique[J]. Journal of Tianjin University, 2009, 42(1):970-974.
[18]赵秀峰,曹景阳,罗慧芬.采用HotDisk测量岩土热物性的实验研究[J].中国测试, 2012, 38(4):106-109.Zhao X F, Cao J Y, Luo H F. Experimental study on measuring thermal properties of rock and soil with HotDisk[J]. China Measurement&Test, 2012, 38(4):106-109.
[19]俞亚南,徐坚,冯建江.粉性土导热系数的室内实验研究[J].浙江大学学报(工学版), 2010, 44(1):180-183.Yu Y N, Xu J, Feng J J. Laboratory experiment on thermal conductivity of silty clay[J]. Journal of Zhenjiang University(Engineering Science), 2010, 44(1):180-183.
[20]李健.基于瞬态平面热源法的土壤热学性质研究[D].武汉:湖北工业大学, 2017.Li J. Study of soil thermal properties based on the transient plane heat source method[D]. Wuhan:Hubei University of Technology, 2017.
[21]宋晓东,张文学.沥青混凝土路面物理除冰雪加热功率优化分析[J].森林工程, 2016, 32(2):75-77.Song X D, Zhang W X. The optimization analysis of heating power for removing ice and snow on asphalt pavement[J]. Journal of Forest Engineering, 2016, 32(2):75-77.
[22]刘焕宝,张喜发,赵意民,等.冻土导热系数热流计法模拟试验及成果分析[J].冰川冻土, 2011, 33(5):1127-1131.Liu H B, Zhang X F, Zhao Y M, et al. Frozen soil thermal conductivity determined by using heat-flow meter:simulation experiment and result analysis[J]. Journal of Glaciology and Geocryology, 2011, 33(5):1127-1131.
[23]杨文,吴涛,方志.单箱多室混凝土箱梁水化热实测与分析[J].公路工程,2017,42(6):254-260.Yang W, Wu T, Fang Z. Measurement and analysis of hydration heat of single-box and multi-chamber concrete box girder[J].Highway Engineering, 2017, 42(6):254-260.
[2]吴金卓,马琳,林文树.生物质发电技术和经济性研究综述[J].森林工程, 2012, 28(5):102-106.Wu J Z, Ma L, Lin W S. Literature review on biomass power generation technology and economic feasibility[J]. Journal of Forest Engineering, 2012, 28(5):102-106.
[3]侯立臣,顾鹂鸣,赵振伟,等.生物质能源林采伐机械化系统与装备发展探讨[J].林业机械与木工设备,2016,44(1):10-12.Hou L C,Gu L M,Zhao Z W,et al.Discussion on development of harvesting mechanization system and equipment for biomass energyforest[J].ForestryMachinery&Woodworking Equipment,2016,44(1):10-12.
[4]WangN,XuD,LiW,etal.Feasibilitystudyofanew thermoelectric conversion device utilizing the temperature differences in forest soi[lJ]. Acta Technica CSAV(Ceskoslovensk Akademie Ved), 2017, 62(1):1-12.
[5]张虎元,张学超,陈晓宁.不同遗址土的热物理参数研究[J].岩土力学, 2014, 35(1):58-62.Zhang H Y, Zhang X C, ChenX N. Research on thermal parameters of different earthen monument soils[J]. Rock and Soil Mechanics, 2014, 35(1):58-62.
[6]李海洋,胡海清,孙龙.我国森林可燃物含水率气象和土壤因子关系模型研究[J].森林工程, 2016, 32(3):1-6.Li H Y, Hu H Q, Sun L. Research on relational models of moisture content of dead forest fuel with meteorological factors and soil factors in China[J]. Journal of Forest Engineering, 2016, 32(3):1-6.
[7]李佳,周祖昊,王浩,等.土壤冻融过程中的多层水热耦合模拟研究[J].水文, 2016, 36(1):1-7.Li J, Zhou Z H, Wang H, et al. Study on simulation of water and heat transfer in soil freezing and thawing[J]. Journal of China Hydrology, 2016, 36(1):1-7.
[8]林梦磊,胡进娣,李爽,等.便携式土壤探测仪的研究[J].森林工程, 2017, 33(5):56-61.Lin M L, Hu J D, Li S, et al. Research of portable forest soil detector[J]. Journal of Forest Engineering, 2017, 33(5):56-61.
[9]肖琳,李晓超,赵晓豹,等.含水量与孔隙率对土体热导率影响的室内实验[J].解放军理工大学学报(自然科学版),2008, 9(3):241-247.Xiao L, Li X C, Zhao X B, et al. Laboratory on influences of moisture content and porosity thermal conductivity of soils[J].Journal of PLA University of Science and Technology, 2008,9(3):241-247.
[10]许欢欢.沥青混凝土面层压实后的孔隙率检测标准研究[J].公路工程,2016,41(4):184-187.Xu H H. Study on the porosity test standard for asphalt concrete surface compaction[J]. Highway Engineering, 2016, 41(4):184-187.
[11]隋晓凤,于明志,彭晓峰.含湿沙导热系数的测试与实验研究[J].热科学与技术, 2009, 8(1):20-24.Sui X F, Yu M Z, Peng X F. Experimental study on thermal conductivity measurement of wet sands[J]. Journal Thermal Science and Technology, 2009, 8(1):20-24.
[12]张海峰.含湿土壤的热物理性质研究[J].太阳能学报,2006, 27(10):1069-1072.Zhang H F. Investigation of the thermal properties of wet porous soils[J]. Acta Energiae Solars Sinica, 2006,27(10):1069-1072.
[13]HanJ,SunQ,XingH,etal.Experimentalstudyon thermophysical properties of clay after high temperature[J].Applied Thermal Engineering, 2017, 111(2):847-854.
[14]Goodhew S, Griffiths R. Analysis of thermal-probe measurements using an iterative method to give sample conductivity and diffusivity data[J]. Applied Energy, 2004, 77(2):205-223.
[15]Putkonen J. Determination of frozen soil thermal properties by heated needle probe[J]. Permafrost and Periglacial Processes,2003, 14(4):343-347.
[16]相方园.土壤孔隙网络模型的程序设计与实现[J].湖北农业科学, 2009, 48(4):974-977.XiangFY.Designandrealizationfornetworkmodel reconstruction of soil pore[J]. Hubei Agricultural Sciences,2009, 48(4):974-977.
[17]王强,戴景民,何小瓦.基于HotDisk方法测量热导率的影响因素[J].天津大学学报, 2009, 42(1):970-974.Wang Q, Dai J M, He X W. Influence factors analysis thermal conductivity measurement with HotDisk technique[J]. Journal of Tianjin University, 2009, 42(1):970-974.
[18]赵秀峰,曹景阳,罗慧芬.采用HotDisk测量岩土热物性的实验研究[J].中国测试, 2012, 38(4):106-109.Zhao X F, Cao J Y, Luo H F. Experimental study on measuring thermal properties of rock and soil with HotDisk[J]. China Measurement&Test, 2012, 38(4):106-109.
[19]俞亚南,徐坚,冯建江.粉性土导热系数的室内实验研究[J].浙江大学学报(工学版), 2010, 44(1):180-183.Yu Y N, Xu J, Feng J J. Laboratory experiment on thermal conductivity of silty clay[J]. Journal of Zhenjiang University(Engineering Science), 2010, 44(1):180-183.
[20]李健.基于瞬态平面热源法的土壤热学性质研究[D].武汉:湖北工业大学, 2017.Li J. Study of soil thermal properties based on the transient plane heat source method[D]. Wuhan:Hubei University of Technology, 2017.
[21]宋晓东,张文学.沥青混凝土路面物理除冰雪加热功率优化分析[J].森林工程, 2016, 32(2):75-77.Song X D, Zhang W X. The optimization analysis of heating power for removing ice and snow on asphalt pavement[J]. Journal of Forest Engineering, 2016, 32(2):75-77.
[22]刘焕宝,张喜发,赵意民,等.冻土导热系数热流计法模拟试验及成果分析[J].冰川冻土, 2011, 33(5):1127-1131.Liu H B, Zhang X F, Zhao Y M, et al. Frozen soil thermal conductivity determined by using heat-flow meter:simulation experiment and result analysis[J]. Journal of Glaciology and Geocryology, 2011, 33(5):1127-1131.
[23]杨文,吴涛,方志.单箱多室混凝土箱梁水化热实测与分析[J].公路工程,2017,42(6):254-260.Yang W, Wu T, Fang Z. Measurement and analysis of hydration heat of single-box and multi-chamber concrete box girder[J].Highway Engineering, 2017, 42(6):254-260.