Thermo-Mass Coupling Fractal Study of Wet Phase-Change Rough Porous Materials
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摘要:
多孔材质复杂的内部结构和含湿状态对传热和传质特性有着重要意义，其热质耦合传递过程广泛存在于能源开发和工程隔热等领域。不同于在多孔材质理想状态下对传热和传质特性的单方面分析，该文将孔道的分布参数、粗糙表面、含湿状态和相变等因素考虑进去，运用分形理论推导出了含湿相变粗糙表面多孔材质的渗流系数和耦合等效导热系数的表达式。结果表明，渗流系数与面积分形维数、含湿饱和度呈正相关，与相对粗糙度、迂曲分形维数呈负相关；耦合等效导热系数与渗流系数、相变量呈正相关，与相对粗糙度呈负相关。此外，结果还表明，相变量以及相变引起的气体膨胀压强差对热质耦合传递也有着重要影响。
Abstract:The complex internal structures and moisture states of porous materials are of great significance to heat and mass transfer, and their coupling heat and mass transfer processes widely exist in energy development and engineering heat insulation. Beyond the unilateral analysis of heat and mass transfer characteristics of porous materials under ideal conditions, the distribution parameters of porous channels, rough surface, wet states and phase-change were considered, and the fractal theory was used to deduce the expressions of the seepage coefficient and the coupling equivalent thermal conductivity of porous materials with wet phase-change rough surface. The results show that, the seepage coefficient is positively correlated with the area fractal dimension and the moisture saturation, and negatively correlated with the relative roughness and the tortuous fractal dimension. The coupling equivalent thermal conductivity is positively correlated with the seepage coefficient and the phase variable, but negatively correlated with the relative roughness. In addition, the phase variable and the gas expansion pressure difference caused by phase-change also have important effects on the coupling heat and mass transfer.
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Key words:
- moisture saturation /
- phase-change /
- rough surface /
- thermo-mass coupling transfer /
- fractal
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图 2 等效导热系数λdeff与孔隙率φ的关系
Figure 2. The relationship between equivalent thermal conductivity λdeff and porosity φ
图 3 面积分形维数Df对环状渗流系数kcw的影响
Figure 3. The influence of area fractal dimension Df on annular seepage coefficient kcw
图 4 迂曲分形维数Dt对环状渗流系数kcw的影响
Figure 4. The influence of tortuous fractal dimension Dt on annular seepage coefficient kcw
图 5 饱和度s对环状渗流系数kcw的影响
Figure 5. The influence of saturation s on annular seepage coefficient kcw
图 6 渗流系数对等效导热系数λdeff的影响
Figure 6. The effect of the seepage coefficient on equivalent thermal conductivity λdeff
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[1] SKURIKHIN A V, KOSTANOVSKY A V. Both numerical and experimental separation of heat transfer mechanisms in porous refractory thermal insulation materials[J]. Journal of Physics: Conference Series, 2020, 1683(4): 042088. doi: 10.1088/1742-6596/1683/4/042088 [2] GAO H, LIU H, LIAO L B, et al. Improvement of performance of foam perlite thermal insulation material by the design of a triple-hierarchical porous structure[J]. Energy & Buildings, 2019, 200: 21-30. [3] 冯守玲, 郑艺华, 张心怡, 等. 多孔材料固定床内温度场的数值模拟研究[J]. 青岛大学学报(工程技术版), 2017, 32(2): 91-95. (FENG Shouling, ZHENG Yihua, ZHANG Xinyi, et al. Numerical simulation of temperature field distribution in packed bed with porous material[J]. Journal of Qingdao University (Engineering & Technology Edition) , 2017, 32(2): 91-95.(in Chinese) [4] 何增, 田宙, 王铁良. 高温高压气体在低含水率介质中迁移的数值模拟[J]. 计算力学学报, 2018, 35(3): 291-298. (HE Zeng, TIAN Zhou, WANG Tieliang. Numerical simulation of gas transport at high temperature and high pressure in porous media with low water content[J]. Chinese Journal of Computational Mechanics, 2018, 35(3): 291-298.(in Chinese) doi: 10.7511/jslx20170413002 [5] 石金诚, 肖胜中. 多孔介质中的一类双扩散扰动模型的解的连续依赖性[J]. 应用数学和力学, 2020, 41(10): 1092-1102. (SHI Jincheng, XIAO Shengzhong. Continuous dependence of solutions to a class of double diffusion perturbation models for porous media[J]. Applied Mathematics and Mechanics, 2020, 41(10): 1092-1102.(in Chinese) [6] 徐鹏, 李翠红, 柳海成, 等. 多尺度多孔介质有效气体输运参数的分形特征[J]. 地球科学, 2017, 42(8): 1373-1378. (XU Peng, LI Cuihong, LIU Haicheng, et al. Fractal features of the effective gas transport coefficient for multiscale porous media[J]. Earth Science, 2017, 42(8): 1373-1378.(in Chinese) [7] LI C H, XU P, QIU S X, et al. The gas effective permeability of porous media with Klinkenberg effect[J]. Journal of Natural Gas Science and Engineering, 2016, 34: 534-540. doi: 10.1016/j.jngse.2016.07.017 [8] 张赛, 陈君若, 刘显茜. 气体有效扩散系数的分形模型[J]. 化学工程, 2013, 41(5): 39-43. (ZHANG Sai, CHEN Junruo, LIU Xianxi. Fractal model of gas effective diffusivity[J]. Chemical Engineering, 2013, 41(5): 39-43.(in Chinese) doi: 10.3969/j.issn.1005-9954.2013.05.009 [9] 陈家豪, 娄钦. 考虑接触角滞后性多孔介质内非混相驱替研究[J]. 应用数学和力学, 2021, 42(9): 900-914. (CHEN Jiahao, LOU Qin. An investigation on the immiscible displacement in porous media with contact angle hysteresis[J]. Applied Mathematics and Mechanics, 2021, 42(9): 900-914.(in Chinese) [10] WU C Q, XU H J, ZHAO C Y. A new fractal model on fluid flow/heat/mass transport in complex porous structures[J]. International Journal of Heat and Mass Transfer, 2020, 162: 120292. doi: 10.1016/j.ijheatmasstransfer.2020.120292 [11] 郑川, 潘标开, 莫红艳. 土壤一维渗流-传热耦合模型实验及数值模拟[J]. 土工基础, 2021, 35(3): 338-342. (ZHENG Chuan, PAN Biaokai, MO Hongyan. One-dimensional soil model test and numerical simulation of coupled seepage-heat transfer model[J]. Soil Engineering and Foundation, 2021, 35(3): 338-342.(in Chinese) [12] 张春平. 粗糙度对微细通道内流动与换热特性影响的实验研究与理论分析[D]. 博士学位论文. 北京: 中国科学院工程热物理研究所, 2007.ZHANG Chunping. Experimental research and theoretical analysis on flow and heat transfer in microchannels with different surface roughness[D]. PhD Thesis. Beijing: Institute of Engineering Thermophysics, Chinese Academy of Sciences, 2007.(in Chinese) [13] 盛汉乾. 基于微波加热沥青路面的传热传质实验装置及质热耦合研究[D]. 硕士学位论文. 芜湖: 安徽工程大学, 2018.SHENG Hanqian. Research on heat and mass transfer experimental device and heat and mass coupling of asphalt pavement based on microwave heating[D]. Master Thesis. Wuhu: Anhui Polytechnic University, 2018.(in Chinese) [14] 郁伯铭, 徐鹏, 邹明清, 等. 分形多孔介质输运物理[M]. 北京: 科学出版社, 2014.YU Boming, XU Peng, ZOU Mingqing, et al. Transport Physics of Fractal Porous Media[M]. Beijing: Science Press, 2014.(in Chinese) [15] MAXWELL J C. A Treatise on Electricity and Magnetism[M]. 3rd ed. New York: Dover Publications Inc, 1954. -
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