| 水基Al2O3纳米流体强化闭式冷却塔内传热过程数值模拟 |
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| 引用本文： | 谢晓翠,刘铭钊,何畅,张冰剑,潘明,陈清林.水基Al2O3纳米流体强化闭式冷却塔内传热过程数值模拟[J].医学教育探索,2018,44(4):524-528,587. |
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| 作者姓名： | 谢晓翠 刘铭钊 何畅 张冰剑 潘明 陈清林 |
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| 作者单位： | 中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275,中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275,中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275,中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275,中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275,中山大学化学工程与技术学院, 广东省石化过程节能工程技术研究中心, 广州 510275 |
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| 基金项目： | 国家自然科学基金石化联合基金项目（U1462113） |
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| 摘 要： | 对以Al2O3纳米流体作为喷淋介质的闭式冷却塔进行了数值模拟，采用流体体积函数（VOF）模型及离散项模型（DPM）作为数值模型进行封闭求解，并分析纳米流体质量浓度和单位时间喷淋量对闭式冷却塔热力学特性的影响。结果表明，随着纳米流体质量分数增加，闭式冷却塔的进口与出口空气含湿量差和单位时间喷淋量均呈现先上升后下降的趋势，在纳米流体质量分数为0.5%时进出口空气含湿量差达到最大值，相比纯水提高了约18.3%；当流体单位时间喷淋量为0.28 kg/s时，闭式冷却塔达到最佳热质传递性能。
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| 关 键 词： | 闭式冷却塔 数值模拟 Al2O3纳米流体 强化传热 |
| 收稿时间： | 2017/8/29 0:00:00 |
Numerical Simulation for Heat Transfer Enhancement by Using Al2O3-Water Nanofluids in Closed Cooling Tower |
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| XIE Xiao-cui,LIU Ming-zhao,HE Chang,ZHANG Bing-jian,PAN Ming and CHEN Qing-lin.Numerical Simulation for Heat Transfer Enhancement by Using Al2O3-Water Nanofluids in Closed Cooling Tower[J].Researches in Medical Education,2018,44(4):524-528,587. |
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| Authors: | XIE Xiao-cui LIU Ming-zhao HE Chang ZHANG Bing-jian PAN Ming and CHEN Qing-lin |
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| Institution: | School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China,School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China,School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China,School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China,School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China and School of Chemical Engineering and Technology, Guangdong Engineering Center for Petrochemical Energy Conservation, Sun Yat-Sen University, Guangzhou 510275, China |
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| Abstract: | Closed wet cooling tower (CWCT) can be considered as a conventional open wet cooling tower in which the filler is replaced by a bank of tubes carrying the process water. In particular, in a CWCT the process water goes inside the tubes, while the ambient air and spray water flow over the external surface of the tubes. As a result, there is no direct contact between the process water and air flows, and the mass and heat transfer primarily occurs only on the tube surface through convection between the spray water and air. This indirect contacting mode ensures that the process water keeps clean and will not be polluted by environment. Currently, closed wet cooling towers (CWCTs) have received substantial research interests and have gained growing industrial concerns due to their clean operating mode and good thermal performances. In this paper, the enhancement effect of Al2O3-water nanofluid used as the spray fluid on the thermal performance of counter-flow CWCTs was investigated numerically. A three-dimensional model of CWCTs was built where VOF and DPM models were employed to calculate vapor-phase flow and the behavior of nanofluids. The influence of the mass fraction of nanofluids and spray mass flow rates on thermodynamic characteristics of CWCTs was analyzed by CFD. The results showed that the humidity difference and spray water mass in CWCTs first increased and then decreased along with the increasing of the concentration of Al2O3 nanofluid. Compared to the pure water, the humidity difference increased by nearly 18.3% when the mass fraction of Al2O3 nanofluid was 0.5%. The heat transfer coefficient increased with the increase of spray water mass rate. The maximum mass transfer coefficient was 0.18 kg/(m2·s) when the spray mass flow rate was 0.28 kg/s. |
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| Keywords: | closed wet cooling towers numerical simulation Al2O3 nanofluids heat transfer enhancement |
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