Ethanol/Gasoline Droplet Heating and Evaporation: Effects of Fuel Blends and Ambient Conditions
Ethanol/Gasoline Droplet Heating and Evaporation: Effects of Fuel Blends and Ambient Conditions
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DOI：
10.1021/acs.energyfuels.8b00366
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发表时间：
2018-06-01
期刊：
影响因子：
5.3
通讯作者：
Ghaleeh, M.
中科院分区：
文献类型：
--
作者：
Al Qubeissi, Mansour;Al-Esawi, Nawar;Ghaleeh, M.
本文主要研究了内燃机典型工况下乙醇/汽油混合燃料液滴的加热和蒸发过程。利用传热学和物质扩散方程的解析解，研究了环境条件(环境压力、环境温度和辐射温度)和乙醇/汽油混合燃料比例对多组分燃料液滴加热和蒸发的影响。在3~30bar、400~650K、1000~2000K和0%(纯汽油)~100%(纯乙醇)的范围内，分别考虑了环境压力、气体温度和辐射温度以及乙醇/汽油燃料比。用离散组分模型计算了21种碳氢化合物的瞬时扩散、温度梯度和液滴内的回流。在所有环境压力(3-30巴)下，随着环境温度的升高，所有混合物的液滴寿命都会缩短。乙醇和汽油燃料的混合对液滴的加热和蒸发有显著影响，在相同条件下，纯乙醇的液滴表面温度比汽油低24.3%，液滴寿命比汽油高33.9%。最后，与忽略辐射的情况相比，考虑辐射的汽油燃料液滴蒸发时间减少了28.6%，乙醇燃料液滴蒸发时间减少了21.8%。
This paper focuses on the modeling of blended ethanol/gasoline fuel droplet heating and evaporation in conditions representative of internal combustion engines. The effects of ambient conditions (ambient pressure, ambient temperature, and radiative temperature) and ethanol/gasoline fuel blend ratios on multicomponent fuel droplet heating and evaporation are investigated using the analytical solutions to the heat-transfer and species diffusion equations. The ambient pressures, gas and radiative temperatures, and ethanol/gasoline fuel ratios are considered in the ranges of 3-30 bar, 400-650 K, 1000-2000 K, and 0% (pure gasoline)-100% (pure ethanol), respectively. Transient diffusion of 21 hydrocarbons, temperature gradient, and recirculation inside droplets are accounted for using the discrete component model. The droplet lifetimes of all mixtures decrease when ambient temperatures increase, under all ambient pressures (3-30 bar). The combination of ethanol and gasoline fuels has a noticeable impact on droplet heating and evaporation; for pure ethanol, the predicted droplet surface temperature is 24.3% lower, and lifetime 33.9% higher, than that for gasoline fuel under the same conditions. Finally, taking into account radiation decreases the gasoline fuel droplet evaporation times by up to 28.6%, and those of ethanol fuel droplets by up to 21.8%, compared to the cases where radiation is ignored.