伞板式降膜蒸发器传热性能的研究
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摘要
本文以水和5％～40％的碳酸钾溶液为工作介质，对伞板式降膜蒸发器的传热性能进行了实验研究。首先对伞板的传热情况进行了理论分析，得出了伞板蒸发侧传热系数的计算式。通过恒壁温实验探讨了传热温差、液膜雷诺数、普朗特数这些主要因素对伞板式降膜蒸发器传热性能的影响，通过对以上影响因素的分析，得出了此种结构的蒸发器特别适用于小温差情况下的蒸发，而且特别适用于热敏性物料的蒸发等特性。同时通过对实验数据的处理，得出了伞板降膜蒸发侧传热系数的实验关联式，此关联式预测的传热系数与实验值吻合良好，误差基本在10％以内。
同时本文还对伞板式降膜蒸发器在小流量下产生的液膜破裂情况进行了理论分析以及实验研究。在实验条件下得出了伞板式降膜蒸发器小流量下液膜破裂的实验关联式，此关联式表明极限热通量随临界雷诺数增大而增大，在相同的临界雷诺数下，伞板蒸发器的极限热通量大于直板形蒸发器的极限热通量。表明此结构的蒸发器在小流量的情况下液膜不易破裂。
The heat transfer performance of the umbrella-plate falling film evaporator was studied, water and concentration of 5%-40% potash was used as medium in this paper. At first, by theoretically analyzing the instance of heat transfer on the umbrella-plate evaporator. The formula of the heat transfer coefficient on the evaporation side in the umbrella-plate could be obtained. The influence of difference in temperature, Reynolds number of film and Prandtl number to the heat transfer performance on the evaporation side was discussed via the uniform wall temperature experiments. By analyzing above influence factors, The character of umbrella-plate evaporator which is fit for evaporation under little difference in temperature and fit for evaporating heat sensitivity materiel could be obtained. The experimental correlation formula of the heat transfer coefficient on the evaporation side in the umbrella-plate was obtained. The predicated heat transfer coefficient through the formula was finely accord with the experimental result, and the error was basically under 10%.
By theoretical analysis and experimental investigation to the exasperate position of the heat transfer in the umbrella-plate falling film evaporator, The exasperate experimental formula of the heat transfer was obtained. With the same Reynolds, The high-point heat flux density of umbrella-plate evaporator is higher than vertical-plate evaporator could be observed from above formula, which maked out that with little Reynolds liquid film was not easy to break.
同时本文还对伞板式降膜蒸发器在小流量下产生的液膜破裂情况进行了理论分析以及实验研究。在实验条件下得出了伞板式降膜蒸发器小流量下液膜破裂的实验关联式，此关联式表明极限热通量随临界雷诺数增大而增大，在相同的临界雷诺数下，伞板蒸发器的极限热通量大于直板形蒸发器的极限热通量。表明此结构的蒸发器在小流量的情况下液膜不易破裂。
The heat transfer performance of the umbrella-plate falling film evaporator was studied, water and concentration of 5%-40% potash was used as medium in this paper. At first, by theoretically analyzing the instance of heat transfer on the umbrella-plate evaporator. The formula of the heat transfer coefficient on the evaporation side in the umbrella-plate could be obtained. The influence of difference in temperature, Reynolds number of film and Prandtl number to the heat transfer performance on the evaporation side was discussed via the uniform wall temperature experiments. By analyzing above influence factors, The character of umbrella-plate evaporator which is fit for evaporation under little difference in temperature and fit for evaporating heat sensitivity materiel could be obtained. The experimental correlation formula of the heat transfer coefficient on the evaporation side in the umbrella-plate was obtained. The predicated heat transfer coefficient through the formula was finely accord with the experimental result, and the error was basically under 10%.
By theoretical analysis and experimental investigation to the exasperate position of the heat transfer in the umbrella-plate falling film evaporator, The exasperate experimental formula of the heat transfer was obtained. With the same Reynolds, The high-point heat flux density of umbrella-plate evaporator is higher than vertical-plate evaporator could be observed from above formula, which maked out that with little Reynolds liquid film was not easy to break.
引文
1．姚玉英．《化工原理》(上册)(第一版)．天津．天津科学技术出版社，1992
2．时钧，汪家鼎，余国琮，等．《化学工程手册》(第二版)(上卷)．北京．化学工业出版，1996
3．海亮，恽世昌．国产降膜蒸发器新进展．北京．食品与机械，2000，(4)
4．Paul E，Minton．Handbook OfEvaporation Technology．NOYES PUBLICATIONS，1986
5．吴金星，董其伍，刘敏珊，等．板壳式降膜蒸发器结构及性能研究．郑州工业大学学报，1997，(18)
6．宋继田．异形竖板上降落液膜蒸发传热的研究．天津轻工业学院硕士论文，1993
7．李德虎．垂直管降膜蒸发传热研究回顾．化工装备技术，1991，15(3)：44～48
8．徐济鋆．沸腾传热和气液两相流．北京．原子能出版社，1993
9．邓鸿，林载祁．垂直管内降膜蒸发传热系数计算式．水处理技术，1988，14(3)：137～143
10．吴锦元，徐洪峰，王树楹．垂直管内降膜沸腾传热的研究．化学工程，1990，18(5)：23～26
11. B X Wang, J T Zhang. Experimental study on the dryout heat flux of falling liquid film. International Journal of Heat and Mass Transfer, 2000 , (43): 1897～1903
12．梁虎，王黎，朱平。多效蒸发系统优化设计研究．化学工程，1997，25(6)：48～51
13．刘殿宇．多效降膜式蒸发设备设计的几个问题．化工设备与管道，2000，37(3)：11～13
14．戚立吾．蒸发系统热力方案优化控制．现代化工，1998，(3)：24～27
15．张永贵，胡亚范．高效节能的热泵技术．应用能源技术，1997，(3)：45～47
16. Ch Mostofizadeh, C Kulick. Use of a new type of heat transfer in process industry. Applied Thermal Engineer, 1998, (18): 857～874
17. DulkerAE. Predicting Heat Transfer Coefficients for Film Flow. Petro/chem.. Engr, 1961, (11): 52～54
18. E N Ganic and K Mastanaiah. Hydrodynamics .and heat transfer in falling film flow. In low Reynolds number flow heat exchangers, 1981, (5): 487～520
19. T Fujita and T Ueda. Heat Transfer to Failing Liquid Film and Film Breakdown. International Journal of Heat and Mass Transfer, 1978, 21 (2) : 97～108
20. E N Ganic and N M Roppo. A Note on Heat Transfer to Falling Liquid Films on Vertical Tubes. Letters in Heat and Mass Transfer, 1980, 7 (2): 145～154
21. A M Trommelen. Heat Transfer to Falling Liquid Films. Chemical Engineering Science, 1967, (23):1152～1154
22. K R Chun and R A Seban. Heat Transfer to Evaporating Liquid Films. Journal of Heat Transfer. Trans. A. S. M. E, 1971, 93 (4): 391～396
23. T Ueda and T Fujita. Heat Transfer to Falling Liquid Film and Film Breakdown Saturated Liquid Film With Nucleate Boiling. International Journal of Heat and Mass Transfer, 1978 , 21 (2): 109～118
24．赵起，林载祁．垂直管降膜蒸发器的传热研究．化学工程，1978，(4)
25．李久耀．竖直长管内降膜蒸发的传热研究．天津轻工业学院硕士论文，1986
26．刘玉军．牛奶降膜蒸发传热的研究．天津轻工业学院硕士论文，1987
27．程丽芳．葡萄糖溶液降膜蒸发传热性能的研究．天津轻工业学院硕士论文，1988
28．毛荣辉．长管内湍流降膜蒸发传热性能的研究．天津轻工业学院硕士论文，1989
29. H C Simpson, G C Beggs, J S Lewis. Evaporation from Fluted Surface. 5th Intern, Symp. On Fresh Water From the Sea. Univertisity ofStrathclgde Glasgowm, Scotland, 1976, (2): 289～300
30. Thomas D G, Young G. Thin Film Evaporation Enhancement by Finned Surfaces. Ind: Chem. Proc, Des, Develop, 1970, 9 (2): 317～322
31. Thomas , D. G. Enhancement of Film Condensation Heat Transfer Rates on Vertical Tubes by Vertical Wires. I. and E. C. Fundamentals, 1976, 6(1): 97～103
32. Fulford G D. The Flow of Liquids in Thin Films. Advances in Chem-Eng, 1964 (5): 51～236
33. Gregoring, R. Film Condensation at Finely Corrugated Surfaces. Includeing Surface Tension Effects. Ang. Met. und Phys, 1954, 5(1): 36～49
34. Richter, R. Variables Influencing the Heat Transfer in a Wiped Film Still. Thesis , Dept. of Mech. Eng. R. P. I , 1968
35. Hawes R I. Development of the Vertical Tube Multi-Effect Process. International Symposium on Fresh Water Fromthe Sea, 1970, (6): 275～289
36. Thomas D G, Alexander L G. Improved High-Performance Fluted Tube for Thin Film Evaporation and Condensation. Desalination, 1970, (8): 13～19
37. Hayes G. Roll waves on a layer of a fluid flowing down a thin tube. Phs. Fluids, 1994, (6): 257～261
38. Unterbergw, Edwards, D K. Evaporation from Falling Saline Water Film in Laminar Transitional Flow. A. I. C. E. J, 1965, (11)
39. H C Simpson, G C Beggs, J S Lewis. Evaporation from Fluted Surface. 5th Intern. Symp. On Fresh Water From the, sea. University of Strathclgde Glasgow, Scotland, 1976, (2): 289～300
40．顾传宝．竖板自由流降膜蒸发流动及传热的实验研究．中国工程热物理学会学术会议论文，1987
41．李桂馥．酒窝形波状竖板自由流降膜蒸发实验研究．中国工程热物理学会学术会议论文，1989
42．罗棣庵．水蒸汽在竖直波纹板内凝结换热的研究．中国工程热物理学会传热传质学学术会议论文，1987
43．乔梁．加螺旋线的竖管降膜蒸发传热性能的研究．河北工业大学硕士论文，2003
44．黄卫星，陈文梅．工程流体力学．化学工业出版社．北京，2001，7
45．Ganic E N, Roppo N N. Letters in Heat and mass Transfer, 1980, (2)
46．沈自求．相似理论及其在化工上的应用．北京：高等教育出版社，1959
47．李丁，刘振义．板式自由流降膜蒸发器中的梯形加热元件．化工设备与管道，2000，(37)
48．刘光启，马连湘，刘杰．化学化工物性数据手册(无机卷)．化学工业出版社．北京，2001，(7)：315～331
49．徐尧润，席华，刘振义．异形竖板上降落液膜破裂特性．中国工程热物理学会传热传质学术会议论文集．湖北：中国工程热物理学会，1995．(4)：74～79
50. DuklerAE, SmithL, ChopraA. Int J Multil Flow, 1984, 10 (5): 585～597
51. MaronDM, Dukler A E. Int J Multi Flow, 1984, 10 (5): 599～621
52．蒋章焰，马同泽，赵嘉旗，等．过冷液膜的换热特性和破断条件．化工学报，1990，(6)：663～667
53. Fujita T, Ueda T. Int J H eat Mass Transs fer, 1978, 97 (2): 21～33
54. Bohn M S, Davis S E. IntHeat Yransfer, 1993, 36(7): 1875～1881
2．时钧，汪家鼎，余国琮，等．《化学工程手册》(第二版)(上卷)．北京．化学工业出版，1996
3．海亮，恽世昌．国产降膜蒸发器新进展．北京．食品与机械，2000，(4)
4．Paul E，Minton．Handbook OfEvaporation Technology．NOYES PUBLICATIONS，1986
5．吴金星，董其伍，刘敏珊，等．板壳式降膜蒸发器结构及性能研究．郑州工业大学学报，1997，(18)
6．宋继田．异形竖板上降落液膜蒸发传热的研究．天津轻工业学院硕士论文，1993
7．李德虎．垂直管降膜蒸发传热研究回顾．化工装备技术，1991，15(3)：44～48
8．徐济鋆．沸腾传热和气液两相流．北京．原子能出版社，1993
9．邓鸿，林载祁．垂直管内降膜蒸发传热系数计算式．水处理技术，1988，14(3)：137～143
10．吴锦元，徐洪峰，王树楹．垂直管内降膜沸腾传热的研究．化学工程，1990，18(5)：23～26
11. B X Wang, J T Zhang. Experimental study on the dryout heat flux of falling liquid film. International Journal of Heat and Mass Transfer, 2000 , (43): 1897～1903
12．梁虎，王黎，朱平。多效蒸发系统优化设计研究．化学工程，1997，25(6)：48～51
13．刘殿宇．多效降膜式蒸发设备设计的几个问题．化工设备与管道，2000，37(3)：11～13
14．戚立吾．蒸发系统热力方案优化控制．现代化工，1998，(3)：24～27
15．张永贵，胡亚范．高效节能的热泵技术．应用能源技术，1997，(3)：45～47
16. Ch Mostofizadeh, C Kulick. Use of a new type of heat transfer in process industry. Applied Thermal Engineer, 1998, (18): 857～874
17. DulkerAE. Predicting Heat Transfer Coefficients for Film Flow. Petro/chem.. Engr, 1961, (11): 52～54
18. E N Ganic and K Mastanaiah. Hydrodynamics .and heat transfer in falling film flow. In low Reynolds number flow heat exchangers, 1981, (5): 487～520
19. T Fujita and T Ueda. Heat Transfer to Failing Liquid Film and Film Breakdown. International Journal of Heat and Mass Transfer, 1978, 21 (2) : 97～108
20. E N Ganic and N M Roppo. A Note on Heat Transfer to Falling Liquid Films on Vertical Tubes. Letters in Heat and Mass Transfer, 1980, 7 (2): 145～154
21. A M Trommelen. Heat Transfer to Falling Liquid Films. Chemical Engineering Science, 1967, (23):1152～1154
22. K R Chun and R A Seban. Heat Transfer to Evaporating Liquid Films. Journal of Heat Transfer. Trans. A. S. M. E, 1971, 93 (4): 391～396
23. T Ueda and T Fujita. Heat Transfer to Falling Liquid Film and Film Breakdown Saturated Liquid Film With Nucleate Boiling. International Journal of Heat and Mass Transfer, 1978 , 21 (2): 109～118
24．赵起，林载祁．垂直管降膜蒸发器的传热研究．化学工程，1978，(4)
25．李久耀．竖直长管内降膜蒸发的传热研究．天津轻工业学院硕士论文，1986
26．刘玉军．牛奶降膜蒸发传热的研究．天津轻工业学院硕士论文，1987
27．程丽芳．葡萄糖溶液降膜蒸发传热性能的研究．天津轻工业学院硕士论文，1988
28．毛荣辉．长管内湍流降膜蒸发传热性能的研究．天津轻工业学院硕士论文，1989
29. H C Simpson, G C Beggs, J S Lewis. Evaporation from Fluted Surface. 5th Intern, Symp. On Fresh Water From the Sea. Univertisity ofStrathclgde Glasgowm, Scotland, 1976, (2): 289～300
30. Thomas D G, Young G. Thin Film Evaporation Enhancement by Finned Surfaces. Ind: Chem. Proc, Des, Develop, 1970, 9 (2): 317～322
31. Thomas , D. G. Enhancement of Film Condensation Heat Transfer Rates on Vertical Tubes by Vertical Wires. I. and E. C. Fundamentals, 1976, 6(1): 97～103
32. Fulford G D. The Flow of Liquids in Thin Films. Advances in Chem-Eng, 1964 (5): 51～236
33. Gregoring, R. Film Condensation at Finely Corrugated Surfaces. Includeing Surface Tension Effects. Ang. Met. und Phys, 1954, 5(1): 36～49
34. Richter, R. Variables Influencing the Heat Transfer in a Wiped Film Still. Thesis , Dept. of Mech. Eng. R. P. I , 1968
35. Hawes R I. Development of the Vertical Tube Multi-Effect Process. International Symposium on Fresh Water Fromthe Sea, 1970, (6): 275～289
36. Thomas D G, Alexander L G. Improved High-Performance Fluted Tube for Thin Film Evaporation and Condensation. Desalination, 1970, (8): 13～19
37. Hayes G. Roll waves on a layer of a fluid flowing down a thin tube. Phs. Fluids, 1994, (6): 257～261
38. Unterbergw, Edwards, D K. Evaporation from Falling Saline Water Film in Laminar Transitional Flow. A. I. C. E. J, 1965, (11)
39. H C Simpson, G C Beggs, J S Lewis. Evaporation from Fluted Surface. 5th Intern. Symp. On Fresh Water From the, sea. University of Strathclgde Glasgow, Scotland, 1976, (2): 289～300
40．顾传宝．竖板自由流降膜蒸发流动及传热的实验研究．中国工程热物理学会学术会议论文，1987
41．李桂馥．酒窝形波状竖板自由流降膜蒸发实验研究．中国工程热物理学会学术会议论文，1989
42．罗棣庵．水蒸汽在竖直波纹板内凝结换热的研究．中国工程热物理学会传热传质学学术会议论文，1987
43．乔梁．加螺旋线的竖管降膜蒸发传热性能的研究．河北工业大学硕士论文，2003
44．黄卫星，陈文梅．工程流体力学．化学工业出版社．北京，2001，7
45．Ganic E N, Roppo N N. Letters in Heat and mass Transfer, 1980, (2)
46．沈自求．相似理论及其在化工上的应用．北京：高等教育出版社，1959
47．李丁，刘振义．板式自由流降膜蒸发器中的梯形加热元件．化工设备与管道，2000，(37)
48．刘光启，马连湘，刘杰．化学化工物性数据手册(无机卷)．化学工业出版社．北京，2001，(7)：315～331
49．徐尧润，席华，刘振义．异形竖板上降落液膜破裂特性．中国工程热物理学会传热传质学术会议论文集．湖北：中国工程热物理学会，1995．(4)：74～79
50. DuklerAE, SmithL, ChopraA. Int J Multil Flow, 1984, 10 (5): 585～597
51. MaronDM, Dukler A E. Int J Multi Flow, 1984, 10 (5): 599～621
52．蒋章焰，马同泽，赵嘉旗，等．过冷液膜的换热特性和破断条件．化工学报，1990，(6)：663～667
53. Fujita T, Ueda T. Int J H eat Mass Transs fer, 1978, 97 (2): 21～33
54. Bohn M S, Davis S E. IntHeat Yransfer, 1993, 36(7): 1875～1881