Experimental determination and numerical simulation of vapor diffusion and emission in loading gasoline into tank

doi:10.11949/j.issn.0438-1157.20160550

Abstract

Abstract:

It was of great significance correctly to predict the vapor diffusion and emission inside the tank for the researches of gasoline evaporation loss and vapor pollution control during the operation of loading gasoline into a tank. Then, two key parameters of the volumetric ratio λ of the displacement mixture gas of the vapor-air to the loaded gasoline and the qualitative ratio η of the evaporation loss to the loaded gasoline were mainly considered. Based on the models of volume of fluid(VOF), mass transfer and RNG k-ε turbulence, the evaporation loss was numerically simulated and experimentally investigated during the splash loading operation, and the oil vapor-air diffusion was analyzed and compared for the different loading exit heights, different loading velocity and the different initial vapor mass fraction. Meanwhile, an experimental system of evaporation loss in loading into a tank was built up to verify the numerical simulation, and the results of the numerical simulation were agreed well with the experimental data. The simulation results furthermore showed that the higher of the loading exit, the greater the qualitative ratio η of the evaporation loss to the loaded gasoline. The qualitative ratio of high exit was at around 0.34% and the qualitative ratio of low exit at around 0.025% by the increase of the loading velocity. The qualitative ratio η of high exit was at around of 0.44%, the qualitative ratio of mid exit at around 0.21% and the qualitative ratio of low exit at around 0.043% by increasing the initial vapor mass fraction. It was recommended that the effect of loading velocity and the initial vapor mass fraction should be considered in API loss formula by using a clean tank and low exit when loading and reducing loading speed appropriately before the loading pipe exit was submerged.

Key words: gasoline, evaporation, diffusion, loading velocity, initial vapor mass fraction, numerical simulation

摘要：

正确预测储油罐收油作业时罐内油气扩散排放规律对研究油品蒸发损耗及污染控制具有重要意义，因而两个关键参数（油罐排放气液比λ及损耗率η）被重点考虑。基于VOF模型、扩散传质模型和RNG k-ε湍流模型，对汽油喷溅式装油损耗进行数值模拟研究。分析比较了不同装油口高度、不同装油速度、不同油罐初始油气浓度条件下罐内的油气扩散规律，并建立汽油装罐蒸发损耗实验平台验证以上数值模拟，模拟值与实验值吻合良好。研究结果表明：装油口位置越高，汽油损耗率η越大，随装油速度增大，高装油口损耗率η最大约为0.34%，低装油口约为0.025%。增大油罐初始油气浓度，高装油口损耗率η最大约为0.44%，中装油口约为0.21%，低装油口约为0.043%。最后建议固定顶油罐大呼吸API损耗评估计算公式考虑装油速度及油罐初始油气浓度对蒸发损耗的影响，并尽量采用低装油口及清洗油罐装油。

关键词: 汽油, 蒸发, 扩散, 装油速度, 初始油气浓度, 数值模拟

CLC Number:

TE85

HUANG Weiqiu, WANG Zhaoli, JI Hong, ZHAO Chenlu, LÜ Aihua, XU Xianyang, WANG Yihong. Experimental determination and numerical simulation of vapor diffusion and emission in loading gasoline into tank[J]. CIESC Journal, 2016, 67(12): 4994-5005.

黄维秋, 王兆利, 纪虹, 赵晨露, 吕爱华, 徐先阳, 王翊红. 汽油装罐油气扩散排放的实验测定及数值模拟[J]. 化工学报, 2016, 67(12): 4994-5005.

References 21

[1]	黄维秋, 赵书华, 吕爱华, 等. 油气回收基础理论及其应用[M]. 北京:中国石化出版社, 2011:89. HUANG W Q, ZHAO S H, LÜ A H, et al. Fundamental Theory of Oil Vapor Recovery and Its Application[M]. Beijing:China Petrochemical Press, 2011:89.
[2]	中华人民共和国国家质量监督检验检疫总局, 环境保护部. 石油炼制工业污染物排放标准:GB 31570-2015[S]. 北京:中国环境科学出版社, 2015. General Administration of Quality Supervision, Environment Protection Department. Emission standard of pollutants for petroleum refining industry:GB 31570-2015[S]. Beijing:China Environment Science Press, 2015.
[3]	中华人民共和国住房和城乡建设部. 石油库设计规范:GB 50074-2014[S]. 北京:中国计划出版社, 2015. Ministry of Housing and Urban-Rural Construction of the People's Republic of China. Code for design of oil depot:GB 50074-2014[S]. Beijing:China Planning Press, 2015.
[4]	黄维秋, 饶原刚, 吕艳丽. 固定顶油罐与油气回收集成工艺研究[J]. 油气储运, 2009, 28(11):20-23, 81, 4. HUANG W Q, RAO Y G, LÜ Y L. Research on integrated process of fixed roof tanks with vapor recovery system[J]. Oil & Gas Storage and Transportation, 2009, 28(11):20-23, 81, 4.
[5]	YAMADA H. Contribution of evaporative emissions from gasoline vehicles toward total VOC emissions in Japan[J]. Science of the Total Environment, 2013, 449:143-149.
[6]	KOYNOV A, KHINAST J G. Micromixing in reactive, deformable bubble and droplet swarms[J]. Chemical Engineering & Technology, 2006, 29(1):13-23.
[7]	DAVIDSON M R, RUDMAN M. Volume of fluid calculations of heat or mass transfer across deforming interfaces in two-fluid flow[J]. Numer. Heat Transfer B, 2002, 41(3/4):291-308.
[8]	WAHEED M A, HENSCHKE M, ANDREAS P. Mass transfer by free and forced convection from single spherical liquid drops[J]. International Journal of Heat and Mass Transfer, 2002, 45(22):4507-4514.
[9]	HAELSSIG J B, ANDRE Y T, THIBAULT J, et al. Direct numerical simulation of interphase heat and mass transfer in multicomponent vapor-liquid flows[J]. International Journal of Heat and Mass Transfer, 2010, 53(19/20):3947-3960.
[10]	朱玲, 陈家庆, 柳岩, 等. 汽油挥发过程的试验分析[J]. 车用发动机, 2011,(2):68-72. ZHU L, CHEN J Q, LIU Y, et al. Experimental analysis of gasoline evaporation process[J]. Vehicle Engine, 2011,(2):68-72.
[11]	HASSANVAND A, HASHEMABADI S H, BAYAT M. Evaluation of gasoline evaporation during the tank splash loading by CFD techniques[J]. International Communications in Heat and Mass Transfer, 2010, 37(7):907-913.
[12]	BANERJEE R, ISAAC K M. Evaluation of turbulence closure schemes for stratified two-phase flow[C]//2003 ASME International Mechanical Engineering Congress and Exposition. Washington DC, 2003.
[13]	LATEB M, MASSON C, STATHOPOULOS T, et al. Comparison of various types of k-ε models for pollutant emissions around a two-building configuration[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2013,(115):9-21.
[14]	赵晨露, 黄维秋, 钟璟, 等. 外浮顶罐油气泄漏的数值模拟[J]. 化工学报, 2014, 65(10):4203-4209. ZHAO C L, HUANG W Q, ZHONG J, et al. Numerical simulation of oil vapor leakage from external floating-roof tank[J]. CIESC Jorunal, 2014, 65(10):4203-4209.
[15]	赵晨露, 黄维秋, 石莉, 等. 内浮顶罐中油气扩散运移的数值模拟[J]. 安全与环境学报, 2015, 15(3):72-77. ZHAO C L, HUANG W Q, SHI L, et al. Numerical simulation of oil vapor diffusion and migration from internal floating-roof tank[J]. Journal of Safety and Environment, 2015, 15(3):72-77.
[16]	KAYS W, CRAWFORD M, WEIGAND B. Convective Heat and Mass Transfer[M]. New York:McGraw-Hill, 2005:121.
[17]	SAMIMI ABIANEH O, CHEN C P, MAHALINGAM S. Modeling of multi-component droplets collision in dense evaporating and non-evaporating sprays[J]. International Journal of Automotive Technology, 2014, 15(7):1091-1100.
[18]	BRACKBILL J U, KOTHE D B, ZEMACH C. A continuum method for modeling surface tension[J]. Journal of Computational Physics, 1992, 100(2):335-354.
[19]	黄维秋, 钟秦. 非稳态油品蒸发的数值分析(Ⅰ)数学模型的建立[J]. 石油学报(石油加工), 2003, 19(6):58-63. HUANG W Q, ZHONG Q. Numerical analysis of petroleum products evaporation under unsteady conditions(Ⅰ):Establishment of mathematic model[J]. Acta Petrolei Sinica(Petroleum Processing Section), 2003, 19(6):58-63.
[20]	黄维秋, 钟秦. 非稳态油品蒸发的数值分析(Ⅱ)数值分析及应用实例[J]. 石油学报(石油加工), 2004, 20(1):52-57. HUANG W Q, ZHONG Q. Numerical analysis of petroleum products evaporation under the unsteady conditions(Ⅱ):Numerical analysis and application examples[J]. Acta Petrolei Sinica(Petroleum Processing Section), 2004, 20(1):52-57.
[21]	U. S. Environmental Protection Agency Office. AP 42 Fifth Edition, Volume I, Chapter:Liquid Storage Tanks[EB/OL]. https://www3.epa.gov/ttn/chief/ap42/ch07/final/c07s01.pdf.