Determination of heat transfer coefficient on water-ice interface under free convection condition
-
摘要: 在冰脊的固结过程中,由于接触面积与温差的大幅提升,冰水之间的换热强度显著增强。本文通过浸没试验对自然对流条件下冰水间的换热系数进行了研究。在试验过程中,对试样内部的温度分布与体积变化分别用温度梯度测试系统与数字图像进行测量。为研究初始条件对换热系数的影响,分别采用不同初始温度与厚度的试样在瞬态热传导的环境下进行测试。试验结果表明,换热系数与表面温差呈指数增长,且在本文试验条件下的变化区间为0.3~175 W/(m2·K)。试样的初始温度及厚度并不是影响换热系数的直接因素,而其根本因素为流-固界面的边界层状态。在自然对流状态下流体的驱动条件是热胀效应,即当边界层存在温度差时,虽然外界并不存在扰动流体状态的因素,但由于液体自身温差引起的密度差进而驱动流体运动并影响了换热系数。随着边界层温度梯度的增加,边界层的影响区域扩大,从而导致了较高的换热系数。Abstract: In ice ridges consolidation, the convective heat flux becomes critical due to the larger contact areas and surface temperature differences compared with those from level ice. In this paper, a submerging experiment was designed to determine the heat transfer coefficient (h) between fresh ice and fresh water in a free convection. A thermistor string was used to measure temperature changes while ice growth was recorded by photograph. To study the factors, the tests were carried out on different ice thickness (4.9 cm to 20.5 cm) and initial temperatures (-20℃ and-32℃). The result shows that the h exponential increased with temperature difference from 0.3 W/(m2·K) to 175 W/(m2·K). On the other hand, the variation of initial thickness and temperature was not a direct influence on h. For convective heat transfer, the boundary layer condition is central for understanding the convection between ice surface and water flowing past it. From the governing equation, the water flow in a free convection is caused by density difference, which is driven by the thermal expansion. A large temperature difference between surface and environmental water creates a thicker boundary layer, which leads to a higher h.
-
Key words:
- hear transfer coefficient /
- free convection /
- temperature gradient /
- water-ice interface
-
Hibler Ⅲ W D, Weeks W F, Mock S J. Statistical aspects of sea-ice ridge distributions[J]. Journal of Geophysical Research, 1972, 77(30):5954-5970. Leppäranta M, Lensu M, Kosloff P, et al. The life story of a first-year sea ice ridge[J]. Cold Regions Science and Technology, 1995, 23(3):279-290. Timco G W, Burden R P. An analysis of the shapes of sea ice ridges[J]. Cold Regions Science and Technology, 1997, 25(1):65-77. Timco G, Croasdale K, Wright B. An overview of first-year sea ice ridges[R]. Ottawa, Canada:National Research Council Canada, NRC Canadian Hydraulics Centre, 2000. 谭冰, 李志军, 卢鹏, 等. 南极冬季威德尔海冰脊的表面形态[J]. 水科学进展, 2012, 23(1):117-123. Tan Bing, Li Zhijun, Lu Peng, et al. Morphology of ice ridges in the Weddell Sea in winter, Antarctica[J]. Advances in Water Science, 2012, 23(1):117-123. 季顺迎, 聂建新, 李锋, 等. 渤海冰脊分析及其设计参数[J]. 中国海洋平台, 2000, 15(6):1-5. Ji Shunying, Nie Jianxin, Li Feng, et al. Analysis of ice ridge and it's design parameters in Bohai Sea area[J]. China Offshore Platform, 2000, 15(6):1-5. Leppäranta M, Hakala R. The structure and strength of first-year ice ridges in the Baltic Sea[J]. Cold Regions Science and Technology, 1992, 20(3):295-311. Høyland K V. Consolidation of first-year sea ice ridges[J]. Journal of Geophysical Research:Oceans, 2002, 107(C6):3062. Strub-Klein L, Sudom D. A comprehensive analysis of the morphology of first-year sea ice ridges[J]. Cold Regions Science and Technology, 2012, 82:94-109. Høyland K V, Løset S. Measurements of temperature distribution, consolidation and morphology of a first-year sea ice ridge[J]. Cold Regions Science and Technology, 1999, 29(1):59-74. Leppäranta M. A review of analytical models of sea-ice growth[J]. Atmosphere-Ocean, 1993, 31(1):123-138. Høyland K V, Jenson A, Liferov P, et al. Physical modeling of first-year ice ridges-Part Ⅰ:production, consolidation and physical properties[C]//Proceedings of the 16th International Conference on Port and Ocean Engineering Under Arctic Conditions. Ottawa, Canada:Port and Ocean Engineering under Arctic Conditions, 2001:1483-1492. Jensen A, Løset S, Høyland K, et al. Physical modeling of first-year ice ridges-Part Ⅱ:mechanical properties[C]//Proceedings of the 16th International Conference on Port and Ocean Engineering Under Arctic Conditions. Ottawa, Canada:Port and Ocean Engineering under Arctic Conditions, 2001:1493-1502. Løset S, Kanestrøm Ø, Pytte T. Model tests of a submerged turret loading concept in level ice, broken ice and pressure ridges[J]. Cold Regions Science and Technology, 1998, 27(1):57-73. Repetto-Llamazares A H V. Review on model ice ridges[C]//Proceedings of the 20th IAHR International Symposium on Ice (IAHR). Lahti, Finland:IAHR, 2010. The Society of Naval Architects. Report of the specialist committee on ice[C]//Proceedings of the 22nd International Towing Tank Conference. Seoul:The Society of Naval Architects, 1999. Høyland K, Knut V. Thermal scaling of ice ridges, some dimensionless numbers[C]//Proceedings of the 19th International Conference on Port and Ocean Engineering under Arctic Conditions. Dalian, China:Port and Ocean Engineering under Arctic Conditions, 2007. 汪贺模, 蔡庆伍, 余伟, 等. 水流量对热轧钢板层流冷却过程对流换热系数的影响[J]. 北京科技大学学报, 2012, 34(12):1421-1425. Wang Hemo, Cai Qingwu, Yu Wei, et al. Effect of water flow rate on the heat transfer coefficient of a hot steel plate during laminar flow cooling[J]. Journal of University of Science and Technology Beijing, 2012, 34(12):1421-1425. 袁俭, 张伟民, 刘占仓, 等. 不同冷却方式下换热系数的测量与计算[J]. 材料热处理学报, 2005, 26(4):115-119. Yuan Jian, Zhang Weimin, Liu Zhancang, et al. The measurement and calculation of heat transfer coefficient under different cooling conditions[J]. Transactions of Materials and Heat Treatment, 2005, 26(4):115-119. Ackley S F, Xie Hongjie, Tichenor E A. Ocean heat flux under Antarctic sea ice in the Bellingshausen and Amundsen Seas:two case studies[J]. Annals of Glaciology, 2015, 56(69):200-210. Maykut G A, Untersteiner N. Some results from a time-dependent thermodynamic model of sea ice[J]. Journal of Geophysical Research, 1971, 76(6):1550-1575. McPhee M G. Turbulent heat flux in the upper ocean under sea ice[J]. Journal of Geophysical Research:Oceans, 1992, 97(C4):5365-5379. Peterson A K, Fer I, McPhee M G, et al. Turbulent heat and momentum fluxes in the upper ocean under Arctic sea ice[J]. Journal of Geophysical Research:Oceans, 2017, 122(2):1439-1456. Lei Ruibo, Li Na, Heil P, et al. Multiyear sea ice thermal regimes and oceanic heat flux derived from an ice mass balance buoy in the Arctic Ocean[J]. Journal of Geophysical Research:Oceans, 2014, 119(1):537-547. 朱德才, 张立文, 裴继斌, 等. 固体界面接触换热系数影响因素的实验研究[J]. 锻压技术, 2008, 33(1):139-143. Zhu Decai, Zhang Liwen, Pei Jibin, et al. Experimental research of influence factors on solid interface thermal contact conductance coefficient[J]. Forging & Stamping Technology, 2008, 33(1):139-143. 侯忠霖, 姚山, 王廷利, 等. 一种铝合金水冷界面换热系数反求方法的研究[J]. 材料热处理学报, 2008, 29(1):157-161. Hou Zhonglin, Yao Shan, Wang Tingli, et al. A method of inverse evaluation for interface heat transfer coefficient between aluminium alloy and cooling water[J]. Transactions of Materials and Heat Treatment, 2008, 29(1):157-161. Yen Y C. Review of thermal properties of snow, ice and sea ice[R]. Hanover, New Hampshire, USA:Cold Regions Research and Engineering Laboratory, Engineer Research and Development Center, 1981. Sharqawy M H, Lienhard J H, Zubair S M. Thermophysical properties of seawater:a review of existing correlations and data[J]. Desalination and Water Treatment, 2010, 16(1/3):354-380.
点击查看大图
计量
- 文章访问数: 606
- HTML全文浏览量: 14
- PDF下载量: 513
- 被引次数: 0