升膜蒸发海水淡化装置传热特性研究
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摘要
随着世界人口的增长以及工农业的发展，淡水需求量与日俱增，解决淡水短缺问题成为了全人类面临的严重挑战。海水淡化技术作为一种最为有效的提供淡水方式正在被越来越多的国家所采用。竖管升膜蒸发技术因为具有传热效率高、传热温差小、低温传热性能优良等特点成为了一种有效的传热方式，并特别适合于利用低温余热。
本文所研究的小型竖管升膜蒸发海水淡化装置可以直接利用柴油机余热作为热源。并且由于它的成膜原理是利用气流向上流动时所引起的牵引力向上拉伸形成的，因此它并不像降膜蒸发一样要依靠重力的作用。因此竖管升膜蒸发装置即使在颠簸的环境中也能够形成稳定的液膜，特别适用于船上使用。
本文首先对升膜蒸发的传热机理作了理论分析，然后通过建立一个小型的竖管升膜蒸发实验台，对升膜蒸发过程进行了实验研究。研究的主要目的是得到影响升膜蒸发的主要数据资料。
本实验采用φ20×2，蒸发段长度为L=2000 mm的HAL77-2A型铝黄铜管作为传热管，在绝对压力为0.01MPa到0.02MPa，传热温差为5到15℃的条件下进行。通过对加热水进出口温度、蒸发管内温度、蒸发段液位、冷凝段液位等实验数据的记录，并整理分析后得出了影响升膜蒸发的因素和趋势。
实验结果表明，在实验参数范围内，在相同的压力和液位下，温差越大换热效果越好；在相同的压力和温差，保证不发生“蒸干”的前提下，液位越低越有利于升膜蒸发；在相同的温差和液位下，绝对压力越小越有利于换热，但对于真空度的要求提高，对设备的硬件条件也要求更高。
As growing of population in the world and development of industry and agriculture, fresh water demand is growing day by day. Solving the problem of fresh water depletion is becoming a crucial challenge. Desalination technique, as a most effective way to supply fresh water, is adopted by more and more countries. Vertical tube climbing film technique becomes an effective heat transfer way for the characteristics of high heat transfer rate, small temperature difference and good heat transfer performance, especially for utilization of low temperature exhaust heat.
The mini-type vertical tube climbing-film evaporation desalination device mentioned in this paper can use directly the exhaust heat of diesel engine as the heat resource. The liquid film is formed by the traction force which is generated by upon-moving steam flow. The advantage makes the climbing-film evaporation desalination device can generate stable film, even in an awag condition, such as sea-going vessel.
At first, the theoretical analysis on heat transfer mechanism of climbing film evaporation is carried out. Then, a minitype climbing film evaporation test rig is built for the measuring of heat transfer rate in order to get the data of various influencing factors on climbing film.
HAL77-2A aluminum brass tubes (φ20×2, length of evaporation zone: 2000mm) are used as the heat transfer tube, and the experiment is carried out with the absolute pressure from 0.01MPa to0.02MPa, and the heat transfer temperature difference from 5℃to 15℃. The factors and tendency influencing climbing film evaporation are analyzed by recording and adjusting the parameters of hot water inlet temperature, evaporation tube inner temperature, evaporation zone liquid level, condensation zone liquid level and so on.
The experiment results indicate that higher temperature difference can bring better heat transfer effect on the condition of same pressure and liquid level. On the same pressure and temperature difference condition, if without the drying out phenomena, the lower liquid level is good for climbing film evaporation. On the same temperature difference and liquid level condition, lower absolute pressure benefits heat transfer, but the vacuum degree is higher..
本文所研究的小型竖管升膜蒸发海水淡化装置可以直接利用柴油机余热作为热源。并且由于它的成膜原理是利用气流向上流动时所引起的牵引力向上拉伸形成的，因此它并不像降膜蒸发一样要依靠重力的作用。因此竖管升膜蒸发装置即使在颠簸的环境中也能够形成稳定的液膜，特别适用于船上使用。
本文首先对升膜蒸发的传热机理作了理论分析，然后通过建立一个小型的竖管升膜蒸发实验台，对升膜蒸发过程进行了实验研究。研究的主要目的是得到影响升膜蒸发的主要数据资料。
本实验采用φ20×2，蒸发段长度为L=2000 mm的HAL77-2A型铝黄铜管作为传热管，在绝对压力为0.01MPa到0.02MPa，传热温差为5到15℃的条件下进行。通过对加热水进出口温度、蒸发管内温度、蒸发段液位、冷凝段液位等实验数据的记录，并整理分析后得出了影响升膜蒸发的因素和趋势。
实验结果表明，在实验参数范围内，在相同的压力和液位下，温差越大换热效果越好；在相同的压力和温差，保证不发生“蒸干”的前提下，液位越低越有利于升膜蒸发；在相同的温差和液位下，绝对压力越小越有利于换热，但对于真空度的要求提高，对设备的硬件条件也要求更高。
As growing of population in the world and development of industry and agriculture, fresh water demand is growing day by day. Solving the problem of fresh water depletion is becoming a crucial challenge. Desalination technique, as a most effective way to supply fresh water, is adopted by more and more countries. Vertical tube climbing film technique becomes an effective heat transfer way for the characteristics of high heat transfer rate, small temperature difference and good heat transfer performance, especially for utilization of low temperature exhaust heat.
The mini-type vertical tube climbing-film evaporation desalination device mentioned in this paper can use directly the exhaust heat of diesel engine as the heat resource. The liquid film is formed by the traction force which is generated by upon-moving steam flow. The advantage makes the climbing-film evaporation desalination device can generate stable film, even in an awag condition, such as sea-going vessel.
At first, the theoretical analysis on heat transfer mechanism of climbing film evaporation is carried out. Then, a minitype climbing film evaporation test rig is built for the measuring of heat transfer rate in order to get the data of various influencing factors on climbing film.
HAL77-2A aluminum brass tubes (φ20×2, length of evaporation zone: 2000mm) are used as the heat transfer tube, and the experiment is carried out with the absolute pressure from 0.01MPa to0.02MPa, and the heat transfer temperature difference from 5℃to 15℃. The factors and tendency influencing climbing film evaporation are analyzed by recording and adjusting the parameters of hot water inlet temperature, evaporation tube inner temperature, evaporation zone liquid level, condensation zone liquid level and so on.
The experiment results indicate that higher temperature difference can bring better heat transfer effect on the condition of same pressure and liquid level. On the same pressure and temperature difference condition, if without the drying out phenomena, the lower liquid level is good for climbing film evaporation. On the same temperature difference and liquid level condition, lower absolute pressure benefits heat transfer, but the vacuum degree is higher..
引文
[1] 杨进．浅谈海水淡化技术与应用．天津科技科学观察．2007：79-80．
[2] 陈荣发．有海洋，我们就有水喝——访中国工程院院士高从勰．科学24小时．2002：4-6．
[3] 王亮军．船舶余热海水淡化浅谈——多效蒸发海水淡化装置的工作原理概述．科学情报开发与经济．2006，16(1)：152-153．
[4] 张志娥．升膜蒸发器的设计与应用．石油炼制．1989，10：1-6．
[5] 王世昌．海水淡化工程．化工进展．2003．
[6] 解利昕，李凭力，王世昌．海水淡化技术现状及各种淡化方法评论．化工进展． 2003，22(1)：1081-1084．
[7] 闻人军，李仲钦，陈益棠．膜脱盐技术源流考．水处理技术．1989，15(2)：63．
[8] 童明光，李青．海水淡化技术及其应用．山东电力高等专科学校校报．2003，6(3)．
[9] 贾海军，姜胜耀，吴少融．双塔竖直蒸发管高温多效蒸发海水淡化实验系统．清华大学学报(自然科学版)．2003，43(10)．
[10] 马乐农．低温多效海水淡化装置技术在电厂的应用．河北电力技术．2005，24(5)．
[11] 严俊杰，王金华，邵树峰．多级闪蒸海水淡化系统的改进研究．西安交通大学学报． 2005，39(11)．
[12] ZYD-30型压汽蒸溜海水淡化装置．
[13] E. Drioli, F. Lagana, A. Criscuoli, G. Barbieri. Integrated Membrane Operations In Desalination Processes. Desalination 1999,122:141-145.
[14] J. M. Ortiz, J. A. Sotoca, E.Exposito. Brackish Water Desalination by Electrodialysis: Batch Recirculation Operation Modeling. Journal of Membrance Science. 2005,252:65-75.
[15] 李凭力，马佳，解利昕，王世昌．冷冻法海水淡化技术新进展．化工进展．2005，24(7)．
[16] Daniel Hoffman. Desulination. 1992, 89: 115-184．
[17] 李毓林，靳国厚．海水淡化现状及应用前景．水利科技与经济．2001，7(4)．
[18] 周少祥，胡三高，宋之平等．海水淡化是解决水资源问题的一个可行途径．北京动力经济学院学报．1994，11(4)：82-94．
[19] 冯广军．海水淡化——解决淡水资源短缺的有效方案[J]．华北电力技术．2005(3)：41-44．
[20] 马学虎．表面处理水平管外海水降膜蒸发传热的初步实验研究[J]．水处理技术． 2004，30(1)：22-25．
[21] 张良军．T型管沸腾传热强化海水淡化器研究．华南理工大学．
[22] A.M. Helal, A.M. El-Nashar, E.S. Al-Katheeri et al. Optimal Design of Hybrid RO/MSF Desalination Plants Part Ⅱ: Results and Discussion [J]. Desalination. 2004, 160:13-27.
[23] 冷骏，王伟勇．穿用海水淡化装置及其现状分析．机电设备．2004(5)：44-46．
[24] M.S. Hanra. Desalination of Seawater Using Nuclear Heat. Desalination. 2000,132:263-268.
[25] G. Fiorenza, V.K. Sharma, G. Braccio. Techno-economic Evaluation of A Solar Powered Water Desalination Plant. Energy Conversion and Management. 2003,44:2217-2240.
[26] 沈超，王厚庆，成珂等．LiBr吸收式空调与海水淡化联合运行装置[J]．节能．2005(3)：3-5．
[27] E. Cardona, A. Piacentino. Optimal Design of Cogeneration Plants for Seawater Desalination[J]. Desalination. 2004,166; 411-426.
[28] F.N. Alasfour, M.A. Darwish, A.O. Bin Amer. Thermal Analysis of ME-TVC+MEE Desalination Systems[J]. Desalination. 200S, 174:39-81.
[29] F. Karl, V. Renaudin, D. Alonso et al. New MED Plate Desalination Process: Thermal Performances[J]. Desalination. 2004,166:53-62.
[30] 张雨山，王静．海水利用技术问答．中国石化出版社．2003．
[31] 王强，郑宏飞，厉彦忠．横管降膜蒸发太阳能海水淡化装置的性能分析．太阳能学报． 2003，24(3)．
[32] 朱玉峰，董金华．竖管降膜蒸发器的性能研究．轻工机械．2005(2)．
[33] 董玉军，包涛，胡跃明等．板式蒸发器换热性能的数值模拟Ⅰ：数学模型．制冷空调电力机械． 2004，25(98)．
[34] 董玉军，包涛，胡跃明等．板式蒸发器换热性能的数值模拟Ⅱ：结果及分析．制冷空调电力机械． 2004，25(98)．
[35] 张建国，张英，李成丽．升膜蒸发器在天然碱制烧碱行业中的应用．化学工业与工程技术． 2000，21(3)．
[36] Schlunder. E.U. Heat Exchanger Design Handbook.
[37] 奚士光，吴味隆，蒋君衍等．锅炉及锅炉房设备．中国建筑工业出版社．2002．
[38] H. Kim, S. Choi. A Model on Water Level Dynamics in Nature Circulation Drum-type Boiler. International Communications in Heat and Mass Transfer. 2005(30):786-796.
[39] Adrian Bejan, Allan D. Kraus. Heat ransfer Handbook.
[40] Chen, J.C. (1963). A Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow. ASME-63-HT-34, ASME, New York.
[41] Forester, H.K., Zuber. Dynamics of Vapor Bubbles and Boiling Heat Transfer. AIChEJ.,1(4):185-196.
[42] Shah, M.M. (1982). Chart Correlation for Saturated Boiling Heat Transfer Equations and Further Study. ASHRAE Tans.,88, pt.1:185-196.
[43] Gungor, K.E., Winterton, R.H.S. (1987). A General Correlation for Flow Boiling in Tubes and Annuli. Int. J. Heat Mass Transfer. 29:351-358.
[44] Cooper. M.G. (1984). Heat Flow Rates in Saturated Nucleate Pool Boiling: A Wide Ranging Examination Using Reduced Properties, in advances in heat transfer, Vol. 16, J. P. Hartnett and T.F. Irvine, eds., Academic Press, New York, PP. 157-239.
[45] Gungor, K.E., Winterton, R.H.S. (1987). Simplified General Correlation for Saturated Flow Boiling and CoMParisons of Correlations with Data, Chem. Res. Des. 65:148-156.
[46] 史美中，王中铮．热交换器原理与设计．东南大学出版社．1996．
[47] 姚玉英等．化工原理．天津大学出版社．天津．1996．
[48] 李微，施小芳，林述英．升膜式蒸发器生产能力的提高[J]．医药工程设计．2006，27(6)．
[2] 陈荣发．有海洋，我们就有水喝——访中国工程院院士高从勰．科学24小时．2002：4-6．
[3] 王亮军．船舶余热海水淡化浅谈——多效蒸发海水淡化装置的工作原理概述．科学情报开发与经济．2006，16(1)：152-153．
[4] 张志娥．升膜蒸发器的设计与应用．石油炼制．1989，10：1-6．
[5] 王世昌．海水淡化工程．化工进展．2003．
[6] 解利昕，李凭力，王世昌．海水淡化技术现状及各种淡化方法评论．化工进展． 2003，22(1)：1081-1084．
[7] 闻人军，李仲钦，陈益棠．膜脱盐技术源流考．水处理技术．1989，15(2)：63．
[8] 童明光，李青．海水淡化技术及其应用．山东电力高等专科学校校报．2003，6(3)．
[9] 贾海军，姜胜耀，吴少融．双塔竖直蒸发管高温多效蒸发海水淡化实验系统．清华大学学报(自然科学版)．2003，43(10)．
[10] 马乐农．低温多效海水淡化装置技术在电厂的应用．河北电力技术．2005，24(5)．
[11] 严俊杰，王金华，邵树峰．多级闪蒸海水淡化系统的改进研究．西安交通大学学报． 2005，39(11)．
[12] ZYD-30型压汽蒸溜海水淡化装置．
[13] E. Drioli, F. Lagana, A. Criscuoli, G. Barbieri. Integrated Membrane Operations In Desalination Processes. Desalination 1999,122:141-145.
[14] J. M. Ortiz, J. A. Sotoca, E.Exposito. Brackish Water Desalination by Electrodialysis: Batch Recirculation Operation Modeling. Journal of Membrance Science. 2005,252:65-75.
[15] 李凭力，马佳，解利昕，王世昌．冷冻法海水淡化技术新进展．化工进展．2005，24(7)．
[16] Daniel Hoffman. Desulination. 1992, 89: 115-184．
[17] 李毓林，靳国厚．海水淡化现状及应用前景．水利科技与经济．2001，7(4)．
[18] 周少祥，胡三高，宋之平等．海水淡化是解决水资源问题的一个可行途径．北京动力经济学院学报．1994，11(4)：82-94．
[19] 冯广军．海水淡化——解决淡水资源短缺的有效方案[J]．华北电力技术．2005(3)：41-44．
[20] 马学虎．表面处理水平管外海水降膜蒸发传热的初步实验研究[J]．水处理技术． 2004，30(1)：22-25．
[21] 张良军．T型管沸腾传热强化海水淡化器研究．华南理工大学．
[22] A.M. Helal, A.M. El-Nashar, E.S. Al-Katheeri et al. Optimal Design of Hybrid RO/MSF Desalination Plants Part Ⅱ: Results and Discussion [J]. Desalination. 2004, 160:13-27.
[23] 冷骏，王伟勇．穿用海水淡化装置及其现状分析．机电设备．2004(5)：44-46．
[24] M.S. Hanra. Desalination of Seawater Using Nuclear Heat. Desalination. 2000,132:263-268.
[25] G. Fiorenza, V.K. Sharma, G. Braccio. Techno-economic Evaluation of A Solar Powered Water Desalination Plant. Energy Conversion and Management. 2003,44:2217-2240.
[26] 沈超，王厚庆，成珂等．LiBr吸收式空调与海水淡化联合运行装置[J]．节能．2005(3)：3-5．
[27] E. Cardona, A. Piacentino. Optimal Design of Cogeneration Plants for Seawater Desalination[J]. Desalination. 2004,166; 411-426.
[28] F.N. Alasfour, M.A. Darwish, A.O. Bin Amer. Thermal Analysis of ME-TVC+MEE Desalination Systems[J]. Desalination. 200S, 174:39-81.
[29] F. Karl, V. Renaudin, D. Alonso et al. New MED Plate Desalination Process: Thermal Performances[J]. Desalination. 2004,166:53-62.
[30] 张雨山，王静．海水利用技术问答．中国石化出版社．2003．
[31] 王强，郑宏飞，厉彦忠．横管降膜蒸发太阳能海水淡化装置的性能分析．太阳能学报． 2003，24(3)．
[32] 朱玉峰，董金华．竖管降膜蒸发器的性能研究．轻工机械．2005(2)．
[33] 董玉军，包涛，胡跃明等．板式蒸发器换热性能的数值模拟Ⅰ：数学模型．制冷空调电力机械． 2004，25(98)．
[34] 董玉军，包涛，胡跃明等．板式蒸发器换热性能的数值模拟Ⅱ：结果及分析．制冷空调电力机械． 2004，25(98)．
[35] 张建国，张英，李成丽．升膜蒸发器在天然碱制烧碱行业中的应用．化学工业与工程技术． 2000，21(3)．
[36] Schlunder. E.U. Heat Exchanger Design Handbook.
[37] 奚士光，吴味隆，蒋君衍等．锅炉及锅炉房设备．中国建筑工业出版社．2002．
[38] H. Kim, S. Choi. A Model on Water Level Dynamics in Nature Circulation Drum-type Boiler. International Communications in Heat and Mass Transfer. 2005(30):786-796.
[39] Adrian Bejan, Allan D. Kraus. Heat ransfer Handbook.
[40] Chen, J.C. (1963). A Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow. ASME-63-HT-34, ASME, New York.
[41] Forester, H.K., Zuber. Dynamics of Vapor Bubbles and Boiling Heat Transfer. AIChEJ.,1(4):185-196.
[42] Shah, M.M. (1982). Chart Correlation for Saturated Boiling Heat Transfer Equations and Further Study. ASHRAE Tans.,88, pt.1:185-196.
[43] Gungor, K.E., Winterton, R.H.S. (1987). A General Correlation for Flow Boiling in Tubes and Annuli. Int. J. Heat Mass Transfer. 29:351-358.
[44] Cooper. M.G. (1984). Heat Flow Rates in Saturated Nucleate Pool Boiling: A Wide Ranging Examination Using Reduced Properties, in advances in heat transfer, Vol. 16, J. P. Hartnett and T.F. Irvine, eds., Academic Press, New York, PP. 157-239.
[45] Gungor, K.E., Winterton, R.H.S. (1987). Simplified General Correlation for Saturated Flow Boiling and CoMParisons of Correlations with Data, Chem. Res. Des. 65:148-156.
[46] 史美中，王中铮．热交换器原理与设计．东南大学出版社．1996．
[47] 姚玉英等．化工原理．天津大学出版社．天津．1996．
[48] 李微，施小芳，林述英．升膜式蒸发器生产能力的提高[J]．医药工程设计．2006，27(6)．