过热液滴闪蒸过程数学模型的建立与应用
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摘要
本文以闪蒸蒸发机理的特殊性为出发点,基于过热液滴闪蒸所需热量由其内部过热能量提供这一理论基础,建立了全新的过热水滴闪蒸的现象学模型,使用MATLAB/Simulink进行求解,通过实验验证其有效性。经计算得出了闪蒸过程中液滴温度、直径、质量、蒸发速率和蒸发率的变化规律,并利用控制变量法,研究初始温度、闪蒸压力和液滴粒径对液滴温度变化、蒸发速率、蒸发率和闪蒸时间的影响,得出了具有代表性的结论。
Considering the particularity of the mechanism of flash evaporation,a new phenomenological model for superheated droplet flash evaporation was built.This model was based on the idea that the heat needed for evaporation was provided by the superheat energy inside the droplet.The model was calculated using MATLAB/Simulink and was validated by experimental data.The evolution of the droplet's temperature,diameter,mass,evaporation rate and flash efficiency was obtained.The influence of initial temperature,evaporation pressure and droplet diameter on the droplet's temperature evolution,evaporation rate,flash efficiency and flash duration time was investigated and representative conclusions were made.
Considering the particularity of the mechanism of flash evaporation,a new phenomenological model for superheated droplet flash evaporation was built.This model was based on the idea that the heat needed for evaporation was provided by the superheat energy inside the droplet.The model was calculated using MATLAB/Simulink and was validated by experimental data.The evolution of the droplet's temperature,diameter,mass,evaporation rate and flash efficiency was obtained.The influence of initial temperature,evaporation pressure and droplet diameter on the droplet's temperature evolution,evaporation rate,flash efficiency and flash duration time was investigated and representative conclusions were made.
引文
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[11]Raju M S.CFD Modeling of Superheated Fuel Sprays[R].Washington,DC:NASA/CR-2008-215289,2008
[2]周致富,吴威涛,王国祥,等.R134a闪蒸喷雾液滴动力学特征实验研究[J].工程热物理学报,2013,34(1):87-90ZHOU Zhifu,WU Weitao,WANG Guoxiang,et al.An Experimental Study on the Droplets Dynamics of Flashing Spray with R134a[J].Journal of Engineering Thermophysics,2013,34(1):87-90
[3]Shin H T,Lee Y P,Jurng J.Spherical-shaped Ice Particle Production by Spraying Water in a Vacuum Chamber[J].Applied Thermal Engineering,2000,20(5):439-454
[4]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):3453-3459GAO Wenzhong,SHI Yaru,HAN Xiaosheng,et al.Droplet Flash Evaporation of Mixed Dehumidification Solutions[J].CIESC Journal,2012,63(11):3453-3459
[5]Gao W Z,Sun W Z,Anderson K,et al.Investigation on Temperature Distribution of Flash Evaporation of LiCl Droplets Released into Vacuum[J].International Journal of Heat and Mass Transfer,2014,74:414-420
[6]Cheng W L,Chen H,Hu L,et al.Effect of Droplet Flash Evaporation on Vacuum Flash Evaporation Cooling:Modeling[J].International Journal of Heat and Mass Transfer,2015,84:149-157
[7]Muthunayagam A E,Ramamurthi K,Robert P J.Modelling and Experiments on Vaporization of Saline Water at Low Temperatures and Reduced Pressures[J].Applied Thermal Engineering,2005,25(5/6):941-952
[8]Adachi M,McDonell V G,Tanaka D,et al.Characterization of Fuel Vapor Concentration Inside a Flash Boiling Spray[C]//International Congress&Exposition;Detroit,Michigan,1997
[9]Zuo B,Gomes A M,Rutland C J.Modelling Superheated Fuel Sprays and Vaporization[J].International Journal of Engine Research,2000,1(4):321-336
[10]Ra Y,Reitz R D.The Application of a Multicomponent Droplet Vaporization Model to Gasoline Direct Injection Engines[J].International Journal of Engine Research,2003,4(3):193-218
[11]Raju M S.CFD Modeling of Superheated Fuel Sprays[R].Washington,DC:NASA/CR-2008-215289,2008