瞬态热线法冰浆热导率的测试分析
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摘要
冰浆作为一种广泛应用的蓄能型两相介质,其热工物性参数测试有着重要的意义.本文基于瞬态热线法和惠斯通电桥,推导了热导率测试的数学模型,开发了溶液热导率测试装置,装置总不确定度在2%以内,通过测试四种标准液体的热导率,实验装置的可靠性得到验证。运用液固两相流热导率经验模型预测了冰浆制备过程溶液的热导率,发现冷却时间越长、载冷剂温度越低和添加剂浓度越小时有助于固相晶粒的生成,溶液含冰率随之增大.随着含冰率的增大,冰浆热导率的实验值与模型预测值总体均呈增大趋势,Jefferey模型的预测值误差相对较小,Skelland模型的预测值误差较大,而在含冰率较小时两个模型的预测则较为准确。
Ice slurry is a widely used two-phase medium of energy storage, and its thermosphysical parameters measurement is of great significance. In this paper, based on the transient hot-wire method and Wheatstone Bridge, the mathematical model of thermal conductivity measurement is deduced,and a device for measuring the thermal conductivity of solution is developed. The total uncertainty of the device is less than 2%. The reliability of the experimental device is verified by measuring the thermal conductivity of four standard liquids. The empirical model of thermal conductivity of liquid-solid two-phase flow is used to predict the thermal conductivity of ice slurry solution,it is found that t the longer the cooling time, the lower the secondary refrigerant temperature and the smaller the additive concentration are helpful to the formation of solid particle, and the higher the ice content of the solution is. With the increase of ice content, the experimental and predicted values of thermal conductivity of ice slurry show an increasing trend. The error of Jefferey model is relatively small,Skelland model is relatively large, while the prediction of two models with small ice content is more accurate.
Ice slurry is a widely used two-phase medium of energy storage, and its thermosphysical parameters measurement is of great significance. In this paper, based on the transient hot-wire method and Wheatstone Bridge, the mathematical model of thermal conductivity measurement is deduced,and a device for measuring the thermal conductivity of solution is developed. The total uncertainty of the device is less than 2%. The reliability of the experimental device is verified by measuring the thermal conductivity of four standard liquids. The empirical model of thermal conductivity of liquid-solid two-phase flow is used to predict the thermal conductivity of ice slurry solution,it is found that t the longer the cooling time, the lower the secondary refrigerant temperature and the smaller the additive concentration are helpful to the formation of solid particle, and the higher the ice content of the solution is. With the increase of ice content, the experimental and predicted values of thermal conductivity of ice slurry show an increasing trend. The error of Jefferey model is relatively small,Skelland model is relatively large, while the prediction of two models with small ice content is more accurate.
引文
[1] SONG Xu, LIU Liuchen, ZHU Tong, et al. Study of Economic Feasibility of a Compound Cool Thermal Storage System Combining Chilled Water Storage and Ice Storage[J]. Proceedings of the National Academy of Sciences,India Section B:Biological Sciences, 2018, 1(63):1-6
[2]吴学红,王春煦,高茂条,等.石蜡-碳纳米管复合材料的热物性研究[J].工程热物理学报,2017, 38(5):167-172WU Xuehong, WANG Chunxu, GAO Maotiao, et al.Study on Thermal Property of Paraffin-carbon Nanotube Composites[J]. Journal of Engineering Thermophysics.2017, 38(5):167-172
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[5]刘明,何潮洪,黄志尧,等.丁酮肟-丁酮、丁酮肟-正己烷体系导热系数的测定[J].高校化学工程学报,2011,25(4):547-553LIU Ming, HE Chaohong, HUANG Zhiyao, et al. Mea-surement of Thermal Conductivity for Systems of Methyl Ethyl Ketoxime with Methyl Ethyl Ketone and N-hexane Separately[J]. Journal of Chemical Engineering of Chinese Universities, 2011, 25(4):547-553
[6] Cheng Wenlong, Zhang Hongze, Zhao Rui. A New Method of Thermal Probe for Thermal Conductivities Measurement Based on Monte Carlo Inversion[J]. Journal of University of Science&Technology of China, 2008,38(4):414-418
[7]刘瑞见,梁坤峰,贾雪迎,等.小型动态制冰机工作过程的结晶特性[J].化工学报,2018, 69(s2):450-458LIU Ruijian, LIANG Kunfeng, JIA Xueying, et al. Crystallization Characteristics of Dynamic Formation Process of Ice Slurry in Small-scale Ice Making Machine[J]. Journal of Chemical Industry and Engineering, 2018, 69(s2):450-458
[8] Jeffrey D J, Conduction Through a Random Suspension of Spheres[J]. Proceedings of the Royal Society of London,1973, 335(1602):355-367
[9] Wasp E J, Solid-Liquid Flow Slurry Pipeline Transportation[M]. Translated Technical Publications, Berlin:James Clerk Maxwell-Garnett, 1977:385-420
[10] Levy F L, Calculating the Thermal Conductivity of Meat and Fish in the Freezing Range[J]. International Journal of Refrigeration, 1982, 5(3):149-154
[2]吴学红,王春煦,高茂条,等.石蜡-碳纳米管复合材料的热物性研究[J].工程热物理学报,2017, 38(5):167-172WU Xuehong, WANG Chunxu, GAO Maotiao, et al.Study on Thermal Property of Paraffin-carbon Nanotube Composites[J]. Journal of Engineering Thermophysics.2017, 38(5):167-172
[3] Ueki Y, Fujita N, Kawai M, et al. Thermal Conductivity of Molten Salt-based Nanofluid[J]. AIP Advances, 2017,7(5):1-7
[4] Azarfar S, Movahedirad S, Sarbanha A A, et al. Low Cost and New Design of Transient Hot-Wire Technique for the Thermal Conductivity Measurement of Fluids[J]. Applied Thermal Engineering, 2016, 05(138):1-31
[5]刘明,何潮洪,黄志尧,等.丁酮肟-丁酮、丁酮肟-正己烷体系导热系数的测定[J].高校化学工程学报,2011,25(4):547-553LIU Ming, HE Chaohong, HUANG Zhiyao, et al. Mea-surement of Thermal Conductivity for Systems of Methyl Ethyl Ketoxime with Methyl Ethyl Ketone and N-hexane Separately[J]. Journal of Chemical Engineering of Chinese Universities, 2011, 25(4):547-553
[6] Cheng Wenlong, Zhang Hongze, Zhao Rui. A New Method of Thermal Probe for Thermal Conductivities Measurement Based on Monte Carlo Inversion[J]. Journal of University of Science&Technology of China, 2008,38(4):414-418
[7]刘瑞见,梁坤峰,贾雪迎,等.小型动态制冰机工作过程的结晶特性[J].化工学报,2018, 69(s2):450-458LIU Ruijian, LIANG Kunfeng, JIA Xueying, et al. Crystallization Characteristics of Dynamic Formation Process of Ice Slurry in Small-scale Ice Making Machine[J]. Journal of Chemical Industry and Engineering, 2018, 69(s2):450-458
[8] Jeffrey D J, Conduction Through a Random Suspension of Spheres[J]. Proceedings of the Royal Society of London,1973, 335(1602):355-367
[9] Wasp E J, Solid-Liquid Flow Slurry Pipeline Transportation[M]. Translated Technical Publications, Berlin:James Clerk Maxwell-Garnett, 1977:385-420
[10] Levy F L, Calculating the Thermal Conductivity of Meat and Fish in the Freezing Range[J]. International Journal of Refrigeration, 1982, 5(3):149-154