Coupling Mechanism of High-Temperature Evaporation of Multi-Component Fuel Droplets

doi:10.12141/j.issn.1000-565X.220206

Abstract

Abstract:

This study took a multi-component composed of high volatility ethanol and low volatility hydrogenated biodiesel and diesel as the research object and investigated the internal vapor bubble dynamics and evaporation characteristics of the individual droplet at high temperatures. The evaporation characteristics of droplet normalized square diameter and droplet lifetime of the blends of hydrogenated biodiesel, ethanol, and diesel were captured by means of the hanging droplet method and high-speed microscopic imaging in a constant temperature heating furnace. The results show that at 773 K, the evaporation is smooth and the droplet volume decreases uniformly. However, at 973 K, tiny bubbles start to form inside the droplet at 0.093 s and gradually increase in size. Tiny bubbles were formed again at 0.767 s and the second rupture occurs at 0.907 s. The rise in ambient temperature contributes to increasing the evaporation rate of fuel droplets and intensifies the micro explosion during evaporation and shortens the evaporation of droplets to a certain extent; the growth of bubbles inside the droplet during evaporation is related to the Rayleigh-Taylor instability at the vapor-liquid interface, and surface tension phenomenon is observed on the surface of droplets. Compared to diesel, the inhibition effect of evaporation is stronger with the increase of hydrogenated biodiesel in binary fuels and compared with binary fuels, ethanol in ternary fuels promotes micro explosions and shortens droplet evaporation. The droplet evaporation of the ternary fuel shows three typical characteristic stages in the order of ethanol domination, ethanol and diesel co-domination and co-evaporation of all three.

Key words: ternary fuel, droplet, evaporation, micro explosion, hanging drop method

CLC Number:

TK421

MEI Deqing, YU Yue, GAO Yaping, et al. Coupling Mechanism of High-Temperature Evaporation of Multi-Component Fuel Droplets[J]. Journal of South China University of Technology(Natural Science Edition), 2023, 51(3): 33-40.

Figures/Tables 11

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References 25

1	SHI W， LI J， HE B， et al ．Biodiesel production from waste chicken fat with low free fatty acids by an integrated catalytic process of composite membrane and sodium methoxide ［J］．Bioresource Technology， 2013， 139： 316-322.
2	SZABADOS G， BERECZKY Á ．Experimental investigation of physicochemical properties of diesel， biodiesel and TBK-biodiesel fuels and combustion and emission analysis in CI internal combustion engine ［J］．Renewable Energy， 2018， 121： 568-578.
3	NABI M N， RASUL M G， ANWAR M， et al ．Energy， exergy， performance， emission and combustion characteristics of diesel engine using new series of non-edible biodiesels ［J］．Renewable Energy， 2019， 140： 647-657.
4	REUTZSCH J， KIEFFER R C， WEIGAND B ．A consistent method for direct numerical simulation of droplet evaporation ［J］．Journal of Computational Physics， 2020， 413： 1-25.
5	孟柯生．生物柴油及其混合燃料的微爆特性研究［D］．合肥：中国科学技术大学， 2019.
6	曹建明，武奎，彭畅．乙醇/生物柴油/柴油混合燃料试验研究［J］．内燃机， 2020（3）： 12-16.
	CAO Jian-ming， WU Kui， PENG Chang ．Experimental research on ethanol/ biodiesel/ diesel blend fuel ［J］．Internal Combustion Engines， 2020（3）： 12-16.
7	耿莉敏，程清波，陈阳，等．生物柴油-柴油-乙醇混合燃料的燃烧与排放特性［J］．中国公路学报， 2018， 31（11）： 236-243.
	GENG Li-min， CHENG Qing-bo， CHEN Yang， et al ．Combustion and emission characteristics of biodiesel-diesel-ethanol fuel blends ［J］．China Journal of Highway and Transport， 2018， 31（11）： 236-243.
8	左磊，梅德清，张登攀，等．加氢生物柴油-乙醇-柴油在高压共轨柴油机上的燃烧与排放特性［J］．西安交通大学学报， 2020， 54（9）： 189-196.
	ZUO Lei， MEI De-qing， ZHANG Deng-pan， et al ．Combustion and emission performance of hydrogenated biodiesel-ethanol-diesel blends in a common rail diesel engine ［J］．Journal of Xi’an Jiaotong University， 2020， 54（9）： 189-196.
9	RAO D K， KARMAKAR S， BASU S ．Bubble dynamics and atomization mechanisms in burning multi-component droplets ［J］．Physics of Fluids， 2018， 30（6）： 1-17.
10	LIU B， WANG X， LIU Y， et al ．Simulation analysis of flow velocity and liquid film of saline wastewater in falling film evaporation ［J］．Environmental Technology & Innovation， 2020， 19： 100790-1-11.
11	KELLER P， BADER A， HASSE C ．The influence of intra-droplet heat and mass transfer limitations in evaporation of binary hydrocarbon mixtures ［J］．International Journal of Heat & Mass Transfer， 2013， 67： 1191-1207.
12	BANERJEE R ．Numerical investigation of evaporation of a single ethanol/iso-octane droplet ［J］．Fuel， 2013， 107： 724-739.
13	HE X， FENG H， LIU Z， et al ．Numerical simulation of the evaporation characteristics of a dimethyl ether droplet in supercritical environment ［J］．Fuel， 2020， 267： 117120-1-11.
14	周昌．高比例生物柴油和二甲醚混合燃料在直喷式柴油机上的试验研究［D］．太原：太原理工大学， 2008.
15	赵治国，解茂昭．泡沫陶瓷中燃油喷雾液滴蒸发混合的数值研究［J］．燃烧科学与技术， 2006（3）： 233-237.
	ZHAO Zhi-guo， XIE Mao-zhao ．Numerical investigation of the spray droplets evaporation and mixing inside ceramic foam ［J］．Journal of Combustion Science and Technology， 2006（3）： 233-237.
16	任泽昱，张磊，任晓华．针对多组分燃料液滴的混合蒸发模型［J］．工程热物理学报， 2018， 39（10）： 2326-2332.
	REN Ze-yu， ZHANG Lei， REN Xiao-hua ．A hybrid multi-component vaporization model for the vaporization simulation of petroleum fuel drops ［J］．Journal of Engineering Thermophysics， 2018， 39（10）： 2326-2332.
17	李明磊，张会强，李佳峰，等．多组分生物燃料液滴蒸发过程研究［J］．工程热物理学报， 2012， 33（12）： 2211-2214.
	LI Ming-lei， ZHANG Hui-qiang， LI Jia-feng， et al ．Vaporization of biofuel-blended multicomponent droplets ［J］‍．Journal of Engineering Thermophysics， 2012， 33（12）： 2211-2214.
18	PATHAK B， BASU S ．Deformation pathways and breakup modes in acoustically levitated bicomponent droplets under external heating ［J］．Physical Review E， 2016， 93（3）： 1-12.
19	OMAR M， DOMINIQUE T， PATRIZIO M， et al ．Investigation on the conditions leading to the micro-explosion of emulsified fuel droplet using two colors LIF method ［J］．Experimental Thermal and Fluid Science， 2020， 116： 110106-1-17.
20	GIRIN A ．Dynamics of the emulsified fuel drop microexplosion ［J］．Atomization and Sprays， 2017， 27（5）： 407-422.
21	HASHIMOTO N， NOMURA H， SUZUKI， et al ．Evaporation characteristics of a palm methyl ester droplet at high ambient temperatures ［J］．Fuel， 2015， 143： 202-210.
22	赵鹏，钱叶剑，陶常法，等．单液滴蒸发实验装置设计及测试技术研究［J］．合肥工业大学学报， 2019， 42（9）： 1164-1168.
	ZHAO Peng， QIAN Ye-jian， TAO Chang-fa， et al ．Experimental study on design and measurement technology of single droplet evaporation device ［J］．Journal of Hefei University of Technology， 2019， 42（9）： 1164-1168.
23	‍ ‍PAPADOPOULOS ‍C ‍E， ‍ ‍A LAZARIDOU， ‍ KOUTSOUMBA A， et al ．Optimization of cotton seed biodiesel quality （critical properties） through modification of its FAME composition by highly selective homogeneous hydrogenation ［J］‍．Bioresource Technology， 2010， 101（6）： 1812-1819.
24	倪兆静，韩恺，庞博，等．高温高压环境下燃油液滴蒸发的特性试验［J］．内燃机学报， 2019， 37（6）： 536-540.
	NI Zhao-jing， HAN Kai， PANG Bo， et al ．Experiment on evaporation characteristics of fuel droplet in high temperature and high pressure environment ［J］．Transactions of CSICE， 2019， 37（6）： 536-540.
25	熊艳，贾志海，蔡小舒．图像分析法测量液滴接触角［J］．计测技术， 2010， 30（2）： 9-11.
	XIONG Yan， JIA Zhi-hai， CAI Xiao-shu ．Measurement of droplet contact angle with image analyzing method ［J］．Metrology & Measurement Technology， 2010， 30（2）： 9-11.

种类	组成	十六烷值	运动黏度（20℃）/（mm²·s^-1）	含氧量^1）/%	低热值/（kJ·kg^-1）	沸点/℃	95%馏程温度/℃
HB	加氢生物柴油	71.21	4.94	11.06	37 384	325~350	360~365
Ethanol	乙醇	8.00	1.60	34.78	27 200	78.3	77~79
Diesel	柴油	52.00	4.22	0.00	42 500	180~370	121~253
HB5	5%HB+95%柴油	52.96	4.26	0.55	42 242
HB7.5	7.5%HB+92.5%柴油	53.44	4.27	0.83	42 116
HB10	10%HB+90%柴油	53.92	4.29	1.11	41 988		132~266
HB10E10	10%HB+10%乙醇+80%柴油	49.52	4.03	4.58	40 458		119~259
HB10E20	10%HB+20%乙醇+70%柴油	45.12	3.77	8.06	38 928

参数	数值
分辨率	1 024×1 024
最短曝光时间/ns	293
最高帧频/（帧·s^-1）	12 500（1 024×1 024）
高感光度	ISO 25 000
灰度色标/bit	12

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