化工学报 ›› 2022, Vol. 73 ›› Issue (7): 3251-3261.doi: 10.11949/0438-1157.20220017

• 能源和环境工程 • 上一篇    下一篇

蒸汽在含有不可溶核和可溶无机盐的细颗粒物表面的核化特性

赵庆杰1(),胡晓红1,2,张超1,2,凡凤仙1,2()   

  1. 1.上海理工大学能源与动力工程学院,上海 200093
    2.上海理工大学上海市动力工程多相流动与传热重点实验室,上海 200093
  • 收稿日期:2022-01-05 修回日期:2022-04-01 出版日期:2022-07-05 发布日期:2022-08-01
  • 通讯作者: 凡凤仙 E-mail:1907725343@qq.com;fanfengxian@usst.edu.cn
  • 作者简介:赵庆杰(1995—),男,硕士研究生,1907725343@qq.com
  • 基金资助:
    国家自然科学基金项目(51976130);上海市科委科研计划项目(13DZ2260900)

Nucleation behavior of water vapor on fine particle containing insoluble core and soluble inorganic salt

Qingjie ZHAO1(),Xiaohong HU1,2,Chao ZHANG1,2,Fengxian FAN1,2()   

  1. 1.School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China
    2.Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China
  • Received:2022-01-05 Revised:2022-04-01 Published:2022-07-05 Online:2022-08-01
  • Contact: Fengxian FAN E-mail:1907725343@qq.com;fanfengxian@usst.edu.cn

摘要:

鉴于生物质直接燃烧和生物质与煤混合燃烧发电过程排放细颗粒物表面通常含有一定量的可溶无机盐,基于经典异质核化理论,综合考虑晶核生长的表面扩散和直接沉积机制建立了改进的蒸汽在包含球形不可溶核和可溶无机盐的细颗粒物表面的异质核化模型,利用数值模拟方法,对4种组分颗粒(不可溶颗粒以及3种含可溶无机盐的颗粒)的异质核化特性进行对比分析。结果表明,在中等接触角条件下,不可溶颗粒的临界晶核形成自由能和临界晶核半径最大,含KCl颗粒次之,含NaCl颗粒再次之,含CaCl2颗粒最小;临界晶核条件下,表面扩散机制与直接沉积机制引起的水分子添加速率之比随颗粒半径的增大先略有增加而后保持不变,随接触角的增大而单调下降。研究还发现,当接触角较小时,含可溶无机盐颗粒的成核临界饱和度低于不可溶颗粒;当接触角较大时,含KCl和NaCl颗粒的成核临界饱和度先后超过不可溶颗粒。

关键词: 颗粒, 成核, 凝结, 不可溶核, 可溶无机盐, 数值模拟

Abstract:

The surfaces of fine particles that emitted from power generation processes with the direct combustion of biomass and with the co-combustion of biomass and coal usually contain a certain amount of soluble inorganic salt. Based on the classical heterogeneous nucleation theory, an improved model for vapor heterogeneous nucleation on the surfaces of particles containing a spherical insoluble core and soluble inorganic salt was developed, taking into account the embryo growth mechanisms of surface diffusion and direct deposition. Using the numerical simulation method, the nucleation behaviors of four types of particles (insoluble particle and three types of particle containing soluble inorganic salt) were compared and analyzed. The results show that in cases of medium contact angles, the critical free energy of embryo formation and the critical embryo radius of an insoluble particle are the largest, followed by the particles containing KCl, NaCl and CaCl2, respectively. Under the condition with critical embryo radii, the ratio of water molecule addition rates due to mechanisms of surface diffusion and direct deposition increases slightly at first and then keeps constant with increasing particle radius, and decreases monotonically with increasing contact angle. It is also found that when the contact angle is small, the critical saturation ratio for nucleation of a particle containing soluble inorganic salt is lower than that of the insoluble particle, whereas when the contact angle is larger, the critical saturation for nucleation of particles containing KCl and NaCl exceeds that of insoluble particles successively.

Key words: particle, nucleation, condensation, insoluble core, soluble inorganic salt, numerical simulation

中图分类号: 

  • X 513

图1

颗粒及蒸汽在颗粒表面异质核化形成晶核示意图"

图2

常温常压下无机盐溶液中水的活度和溶液的气-液界面自由能"

表1

常温常压下无机盐溶液中水的活度和溶液的气-液界面自由能计算系数"

参数符号NaClKClCaCl2
活度a1-0.5286-0.3818-0.5507
a2-1.0298-0.77881.3166
a3-1.73300-17.9406
a40021.6473
气-液界面自由能B/(N·kg/(m·mol))1.6200×10-31.4923×10-33.4372×10-3

表2

数值模拟采用的计算参数"

参数符号单位数值
温度TK298.15
压力pPa101325
颗粒中不可溶核的密度ρpkg/m32400
可溶无机盐质量分数fs%20
单个水分子的质量mwkg2.99×10-26
单个水分子的体积Vwm32.99×10-29
水分子的平均跳跃距离δm3.2×10-10
水分子的振动频率υHz1×1013
单个水分子的表面扩散能ΔGdiffJ2.9×10-21
单个水分子的吸附能ΔGdesJ2.9×10-20

图3

无量纲晶核形成自由能随晶核半径的变化关系"

图4

直接沉积和表面扩散机制引起的分子添加速率之比"

图5

成核临界饱和度"

1 Yang W, Pudasainee D, Gupta R, et al. An overview of inorganic particulate matter emission from coal/biomass/MSW combustion: sampling and measurement, formation, distribution, inorganic composition and influencing factors[J]. Fuel Processing Technology, 2021, 213: 106657.
2 Wu Z H, Fan F X, Yan J P, et al. An adaptable direct simulation Monte Carlo method for simulating acoustic agglomeration of solid particles[J]. Chemical Engineering Science, 2022, 249: 117298.
3 Lu M S, Fang M X, He M C, et al. Visualization research on electric agglomeration characteristics of fine particles[J]. Powder Technology, 2018, 333: 115-121.
4 Fan F X, Zhang S H, Wang W Y, et al. Numerical investigation of PM2.5 size enlargement by heterogeneous condensation for particulate abatement[J]. Process Safety and Environmental Protection, 2019, 125: 197-206.
5 Fan F X, Zhang S H, Peng Z B, et al. Numerical investigation of heterogeneous nucleation of water vapour on PM10 for particulate abatement[J]. The Canadian Journal of Chemical Engineering, 2019, 97(4): 930-939.
6 王健, 潘伶, 王帅, 等. 工程相变凝并器内超细颗粒长大与脱除性能分析[J]. 化工学报, 2020, 71(11): 5090-5098.
Wang J, Pan L, Wang S, et al. Analysis of ultrafine particles growth and removal in phase-transition agglomerator for engineering[J]. CIESC Journal, 2020, 71(11): 5090-5098.
7 Fan F X, Yang L J, Yan J P, et al. Experimental investigation on removal of coal-fired fine particles by a condensation scrubber[J]. Chemical Engineering and Processing: Process Intensification, 2009, 48(8): 1353-1360.
8 Liu J, Chen D L, Lu J D. Experiment on fine particle purification by flue gas condensation for industrial boilers[J]. Fuel, 2017, 199: 684-696.
9 Zhang Y M, Yu G Y, Jin R Z, et al. Investigation into water vapor and flue gas temperatures on the separation capability of a novel cyclone separator[J]. Powder Technology, 2020, 361: 171-178.
10 Zhang C, Ma N, Fan F X, et al. Hygroscopic growth of aerosol particles consisted of oxalic acid and its internal mixture with ammonium sulfate for the relative humidity ranging from 80% to 99.5%[J]. Atmospheric Environment, 2021, 252: 118318.
11 Qian M, Ma J. Heterogeneous nucleation on convex spherical substrate surfaces: a rigorous thermodynamic formulation of Fletcher's classical model and the new perspectives derived[J]. The Journal of Chemical Physics, 2009, 130(21): 214709.
12 Ruckenstein E, Berim G O, Narsimhan G. A novel approach to the theory of homogeneous and heterogeneous nucleation[J]. Advances in Colloid and Interface Science, 2015, 215: 13-27.
13 Maximoff S N, Salehi A, Rostami A A. Molecular dynamics simulations of homogeneous nucleation of liquid phase in highly supersaturated propylene glycol vapors[J]. Journal of Aerosol Science, 2021, 154: 105743.
14 余廷芳, 高巨, 熊桂龙, 等. 基于分子运动学的水汽在细颗粒表面异质核化的数值模拟[J]. 化工学报, 2020, 71(7): 3071-3079.
Yu T F, Gao J, Xiong G L, et al. Numerical simulation of heterogeneous nucleation of water vapor on surface of fine particles based on molecular kinetics[J]. CIESC Journal, 2020, 71(7): 3071-3079.
15 郭阳, 凡凤仙, 张超, 等. 氨法脱硫系统排放细颗粒物的异质核化特性[J]. 动力工程学报, 2022, 42(1): 49-55.
Guo Y, Fan F X, Zhang C, et al. Heterogeneous nucleation behavior of fine particles from ammonia-based desulfurization system[J]. Journal of Chinese Society of Power Engineering, 2022, 42(1): 49-55.
16 Fletcher N H. Size effect in heterogeneous nucleation[J]. The Journal of Chemical Physics, 1958, 29(3): 572-576.
17 Gorbunov B, Hamilton R. Water nucleation on aerosol particles containing both soluble and insoluble substances[J]. Journal of Aerosol Science, 1997, 28(2): 239-248.
18 Fan F X, Yang L J, Yan J P, et al. Numerical analysis of water vapor nucleation on PM2.5 from municipal solid waste incineration[J]. Chemical Engineering Journal, 2009, 146(2): 259-265.
19 颜金培, 杨林军, 凡凤仙, 等. 基于分形理论的水汽在燃煤细颗粒表面异质核化数值研究[J]. 中国电机工程学报, 2009, 29(11): 50-56.
Yan J P, Yang L J, Fan F X, et al. Numerical analysis of water vapor nucleation on fine particles from coal combustion based on fractal model[J]. Proceedings of the CSEE, 2009, 29(11): 50-56.
20 Iwamatsu M. Line-tension-induced scenario of heterogeneous nucleation on a spherical substrate and in a spherical cavity[J]. The Journal of Chemical Physics, 2015, 143(1): 014701.
21 Luo X S, Fan Y, Qin F H, et al. A kinetic model for heterogeneous condensation of vapor on an insoluble spherical particle[J]. The Journal of Chemical Physics, 2014, 140(2): 024708.
22 凡凤仙, 杨林军, 袁竹林, 等. 水汽在细微颗粒表面异质核化数值分析[J]. 东南大学学报(自然科学版), 2007, 37(5): 833-838.
Fan F X, Yang L J, Yuan Z L, et al. Numerical analysis of water vapor nucleation on fine particles[J]. Journal of Southeast University (Natural Science Edition), 2007, 37(5): 833-838.
23 Pruppacher H R, Klett J D. Microphysics of Clouds and Precipitation[M]. 2nd ed. New York: Springer, 2010: 100-135.
24 Clegg S L, Brimblecombe P, Wexler A S. Thermodynamic model of the system H+-NH4 +-Na+-SO4 2--NO3 --Cl--H2O at 298.15 K[J]. The Journal of Physical Chemistry A, 1998, 102(12): 2155-2171.
25 Zuend A, Marcolli C, Luo B P, et al. A thermodynamic model of mixed organic-inorganic aerosols to predict activity coefficients[J]. Atmospheric Chemistry and Physics, 2008, 8(16): 4559-4593.
26 Määttänen A, Vehkamäki H, Lauri A, et al. Two-component heterogeneous nucleation kinetics and an application to Mars[J]. The Journal of Chemical Physics, 2007, 127(13): 134710.
27 Lv L, Zhang J, Xu J C, et al. Effects of surface topography of SiO2 particles on the heterogeneous condensation process observed by environmental scanning electron microscopy[J]. Aerosol Science and Technology, 2021, 55(8): 920-929.
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