Abstract:A single droplet phase transformation model was developed for moving droplets based on the physical evaporation mechanism of the droplet phase transformation while moving in a steam-water separation plant, the model combined a static droplet phase transformation model with pressure variations and a droplet motion model. The model gives mathematical expressions for the mechanisms during the fast evaporation stage and the thermally controlled evaporation stage during the droplet movement. The pressure decreases due to the flow resistance and local structural changes, which breaks the liquid-vapor phase equilibrium. The results agree with the existed theoretical analysis. This model can be applied to separation efficiency calculations for droplets moving in steam-water separators including gravity separation, cyclone and rotary vane separators and wave plate separators, and can predict the influence of the droplet phase transformation on the separation characteristics to guide structure optimization and design of separation equipment.
赵富龙, 赵陈儒, 薄涵亮. 单液滴运动相变模型[J]. 清华大学学报(自然科学版), 2016, 56(11): 1213-1219.
ZHAO Fulong, ZHAO Chenru, BO Hanliang. Single droplet phase transformation model during motion. Journal of Tsinghua University(Science and Technology), 2016, 56(11): 1213-1219.
张谨奕. 三维流场中单液滴运动模型和应用研究[D]. 北京:清华大学, 2012.ZHANG Jinyi. Study of Single Droplet Motion Model and Application in Three-Dimensional Flow Field[D]. Beijing:Tsinghua University, 2012. (in Chinese)
[2]
Erbil H Y. Evaporation of pure liquid sessile and spherical suspended drops:a review[J]. Advances in Colloid and Interface Science, 2012, 170(1):67-86.
[3]
Gopireddy S R, Gutheil E. Numerical simulation of evaporation and drying of a bi-component droplet[J]. International Journal of Heat and Mass Transfer, 2013, 66:404-411.
[4]
王宝和, 李群. 单液滴蒸发研究的现状与展望[J]. 干燥技术与设备, 2014, 12(4):25-31.WANG Baohe, LI Qun. Present status and prospect of studies on single droplet evaporation[J]. Drying Technology & Equipment, 2014, 12(4):25-31. (in Chinese)
[5]
王遵敬. 蒸发与凝结现象的分子动力学研究及实验[D]. 北京:清华大学, 2002.WANG Zunjing. Molecular Dynamics Research and Experiment of Evaporation and Condensation[D]. Beijing:Tsinghua University, 2002. (in Chinese)
[6]
高文忠, 时亚茹, 韩笑生, 等. 混合除湿盐溶液液滴闪蒸机理[J]. 化工学报, 2012, 63(11):3453-3459.GAO Wenzhong, SHI Yaru, HAN Xiaosheng, et al. Droplet flash evaporation of mixed dehumidification solutions[J]. CIESC Journal, 2012, 63(11):3453-3459. (in Chinese)
[7]
冉景煜, 张志荣. 不同物性液滴在低温烟气中的蒸发特性数值研究[J]. 中国电机工程学报, 2010, 30(26):62-68.RAN Jingyu, ZHANG Zhirong. Numerical study on evaporation characteristics of different substance droplet in low temperature flue gas[J]. Proceedings of the CSEE, 2010, 30(26):62-68. (in Chinese)
[8]
王健, 仇性启, 申玉辉. 急冷器内液滴运动蒸发的数值模拟[J]. 石油化工, 2011, 40(10):1073-1077.WANG Jian, QIU Xingqi, SHEN Yuhui. Numerical simulation of motion and evaporation of the droplets in quencher[J]. Petrochemical Technology, 2011, 40(10):1073-1077. (in Chinese)
[9]
Abramzon B, Sirignano W A. Droplet vaporization model for spray combustion calculations[J]. International Journal of Heat and Mass Transfer, 1989, 32(9):1605-1618.
[10]
Kryukov A P, Levashov V Y, Sazhin S S. Evaporation of diesel fuel droplets:Kinetic versus hydrodynamic models[J]. International Journal of Heat and Mass Transfer, 2004, 47(12):2541-2549.
[11]
Sazhin S S, Abdelghaffar W A, Sazhina E M, et al. Models for droplet transient heating:effects on droplet evaporation, ignition, and break-up[J]. International Journal of Thermal Sciences, 2005, 44(7):610-622.
[12]
Sazhin S S, Abdelghaffar W A, Krutitskii P A, et al. New approaches to numerical modelling of droplet transient heating and evaporation[J]. International Journal of Heat and Mass Transfer, 2005, 48(19-20):4215-4228.
[13]
Sazhin S S, Kristyadi T, Abdelghaffar W A, et al. Models for fuel droplet heating and evaporation:Comparative analysis[J]. Fuel, 2006, 85(12):1613-1630.
[14]
Sazhin S S, Shishkova I N, Kryukov A P, et al. Evaporation of droplets into a background gas:Kinetic modeling[J]. International Journal of Heat and Mass Transfer, 2007, 50(13):2675-2691.
[15]
Irannejad A, Jaberi F. Numerical study of high speed evaporating sprays[J]. International Journal of Multiphase Flow, 2015, 70:58-76.
[16]
Yin C. Modelling of heating and evaporation of n-heptane droplets:Towards a generic model for fuel droplet/particle conversion[J]. Fuel, 2015, 141:64-73.
[17]
Perrin L, Castanet G, Lemoine F. Characterization of the evaporation of interacting droplets using combined optical techniques[J]. Experiments in Fluids, 2015, 56(2):1-16.
[18]
Zhou Z, Wang G, Chen B, et al. Evaluation of evaporation models for single moving droplet with a high evaporation rate[J]. Powder Technology, 2013, 240:95-102.
[19]
Negeed E R, Albeirutty M, Takata Y. Dynamic behavior of micrometric single water droplets impacting onto heated surfaces with TiO<sub>2</sub> hydrophilic coating[J]. International Journal of Thermal Sciences, 2014, 79:1-17.
[20]
Gopireddy S R, Humza R M, Gutheil E. Modeling and simulation of evaporating spray flows with coalescence in an eulerian framework[J]. Chemie Ingenieur Technik, 2012, 84(3):349-356.
[21]
Sazhin S S. Advanced models of fuel droplet heating and evaporation[J]. Progress in Energy and Combustion Science, 2006, 32(2):162-214.
[22]
Zhao F, Liu Q, Bo H. Parameter analysis of the static droplets phase transformation under the pressure variation condition[C]//ASME. ICONE 24. Charlotte:American Society of Mechanical Engineers, 2016:1-12.
[23]
马超. 自由液面单气泡破裂产生膜液滴现象实验与理论研究[D]. 北京:清华大学, 2014.MA Chao. Experimental and Theoretical Research About the Phenomenon of the Film Drops Produced by Bubble Bursting at a Free Water Surface[D]. Beijing:Tsinghua University, 2014. (in Chinese)
[24]
Cole P R. Droplet Evaporation in a Quiescent, Micro-gravity Atmosphere[D]. Lansing:Michigan State University, 2006.
[25]
Semenov S, Starov V, Rubio R G, et al. Computer Simulations of Quasi-steady Evaporation of Sessile Liquid Droplets[M]. London:Springer Berlin Heidelberg, 2011.
[26]
Linán A. Theory of Droplet Vaporization and Combustion[M]. Paris:Eyrolle, 1985.
[27]
崔成松, 蒋祖龄, 沈军, 等. 雾化过程气体与金属雾滴的三维流动模型[J]. 金属学报, 1994, 30(19):294-300.CUI Chengsong, JIANG Zuling, SHEN Jun, et al. Modelling of three-dimensional flow of atomizing gas and droplets in atomization process[J]. Acta Metallurgica Sinica, 1994, 30(19):294-300. (in Chinese)
[28]
张谨奕, 薄涵亮. 重力分离空间均匀流中液滴行为问题研究[J]. 原子能科学技术, 2010, 44(S1):293-297.ZHANG Jinyi, BO Hanliang. Investigation on droplets behavior in uniform flow of gravity separation space[J]. Atomic Energy Science and Technology, 2010, 44(S1):293-297. (in Chinese)
[29]
张璜. 多液滴运动和碰撞模型研究[D]. 北京:清华大学, 2015.ZHANG Huang. Motion and Collision Models of Polydispersed Droplets[D]. Beijing:Tsinghua University, 2015. (in Chinese)
[30]
张谨奕, 薄涵亮, 孙玉良, 等. 三维空间液滴运动模型[J]. 清华大学学报(自然科学版), 2013, 53(1):96-101.ZHANG Jinyi, BO Hanliang, SUN Yuliang, et al. Three-dimensional droplet motion model[J]. Journal of Tsinghua University(Science and Technology), 2013, 53(1):96-101. (in Chinese)
[31]
Zhang T. Study on Surface Tension and Evaporation Rate of Human Saliva, Saline, and Water Droplets[D]. Charlottesvill:West Virginia University, 2011.
[32]
波林, 普劳斯尼茨, 奥康奈尔, 等. 气液物性估算手册[M]. 赵红玲, 译. 北京:化学工业出版社, 2006.Poling B E, Prausnitz J M, O'connell J P, et al. The Properties of Gases and Liquids[M]. Translated by ZHAO Hongling. Beijing:Chemical Industry Press, 2006. (in Chinese)
[33]
Marek R, Straub J. Analysis of the evaporation coefficient and the condensation coefficient of water[J]. International Journal of Heat and Mass Transfer, 2001, 44(1):39-53.
[34]
Liu L, Bi Q, Liu W, et al. Experimental and theoretical investigation on rapid evaporation of ethanol droplets and kerosene droplets during depressurization[J]. Microgravity Science and Technology, 2011, 23(1):89-97.
[35]
陈军亮, 薛运奎, 王先元, 等. 百万千瓦级压水堆核电厂蒸汽发生器汽水分离装置热态验证试验[J]. 核动力工程, 2006, 27(3):61-66.CHEN Junliang, XUE Yunkui, WANG Xianyuan, et al. Proof test in hot condition on steam separation device in steam generator for 1000 MW PWR nuclear power plant[J]. Nuclear Power Engineering, 2006, 27(3):61-66. (in Chinese)