A model for droplet heating and evaporation of water-in-oil emulsified fuel

FUEL

卷:266

Article

Shen, Shiquan^1,2  Che, Zhizhao¹  Wang, Tianyou¹  Yue, Zongyu²  Sun, Kai¹  Som, Sibendu² 

[1] Tianjin Univ, State Key Lab Engines, Tianjin 300072, Peoples R China

[2] Argonne Natl Lab, Energy Syst Div, 9700 South Cass Ave,Bldg 362, Argonne, IL 60439 USA

关键词: Emulsified fuel;    Evaporation model;    Droplet evaporation;    Droplet coalescence;    Droplet micro-explosion;   

DOI  :  10.1016/j.fuel.2019.116710

来源: Elsevier

【 摘 要 】

Water-in-oil (W/O) emulsified fuel is a promising alternative fuel by inducing flash boiling of water at high temperature that can improve the atomization of fuel spray. The heating and evaporation process of emulsified fuel droplet is affected by the diffusion and coalescence of small dispersed water droplets in oil during the heating. In this study, a model is developed for the droplet heating and evaporation of W/O emulsified fuel with these key physics considered. The diffusivity of dispersed water droplets in oil is calculated using the Stokes-Einstein equation. The deactivation temperature of surfactant is selected as a criterion for the water coalescence since the water coalescence is due to the deactivation of surfactant. The process of water coalescence is simplified that the dispersed water droplets coalesce into one single water sub-droplet at the center of the oil droplet instantly as the droplet temperature reaches the deactivation temperature of surfactant. The model is validated against experimental data of single droplet under different heating temperatures, surfactant concentrations, and sizes of dispersed water droplets. Based on the proposed model, the effects of fuel properties and heating conditions on the droplet heating and evaporation are analyzed.

【 授权许可】

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