臺灣博碩士論文加值系統

本研究以微紋影法探討生質油微粒產生機制。液體燃料特性影響噴霧燃燒或是液滴燃燒的特性，這些液滴特性包括：組成、飽和蒸氣壓、沸點、閃火點與黏滯係數等，當中黏滯係數的高低影響噴霧特性的好壞，而液體燃料組成特性，影響燃料的蒸發、閃火引燃與燃燒傳遞的特性。而再生能源的議題響起時，生質能源如何能夠取代化石燃料的使用變成一個重要的議題。生質物裂解油是由纖維素生質物經過熱分解產製而得，然而生質油的組份相當複雜，跟其料源與熱分解的程序參數有關，且在使用上產生了許多問題，包括微粒(soot)、結焦、腐蝕等。本研究探討快慢速裂解生質油並以直接影像與紋影法同步技術觀測液滴燃燒的微粒產生特性。在GC-MS、TGA及FT-IR量測結果顯示裂解生質油主要由多環化合物組成，包括：烷烴、芳香烴、酚類與醛類等，這類的組分是燃料燃燒時微粒(soot)生成的前驅物，並且燃燒過程中受到生質油組份揮發物沸點、閃火點差異(主要為多環化合物，如：芳香烴、烷烴、酚類以及醛類等)與微粒生成影響，形成不同階段液滴燃燒速率。由直接影像觀測液滴燃燒，不論是快慢速裂解生質油，其液滴火焰包覆整個液滴周圍，並且燃燒過程出現一次、二次微爆現象。在重力場條件下受到浮力與自然對流影響，使得燃燒液滴生成的微粒被吹離液滴周圍，且整體被可視火焰可見光影響不易觀察，由同步高速拍攝方式與光學紋影觀測能夠清楚觀測液滴燃燒時流場與擴散作用下的密度變化。比較紋影影像結果顯示，當中微粒尾的定義為火焰影像間明顯邊界，微粒以煙尾狀形成且分佈在可視火焰內側，而熱邊界位置則在可視火焰外側，圍繞在燃燒液滴的下圓則是由燃料以及氧化劑間的擴散與反應的化學作用形成的停滯平面是為史蒂芬流。並且慢速裂解生質油以多環芳香烴為主要組份，影響加速微粒生成。另一部分微粒煙尾影響生質油液滴火焰至液滴表面的熱傳，微粒碳黑輻射從而促進熱交換，從快速熱裂解生質油液滴微粒煙尾顯著形成時顯示，其表面沸點溫度趨向不穩定且溫度上升斜率顯著增加。此外受到組份與微粒煙尾的影響，生質油液滴燃燒過程微粒煙尾的形成以及其邊界顯著形成影響其密度改變導致不同階段的Grashof number(Grashof number(Gr)為探討自然對流時重要的參數)。Gr比較顯示慢速裂解生質油燃燒過程受到浮力影響為大，其密度改變與微粒煙尾流體上升是為顯著，而生質油液滴燃燒，隨著燃燒時間演進，更多的低碳鏈組分參與反應以及微粒煙尾逐漸形成，由組分影響微粒煙尾流的形成將其密度與受浮力影響特性分為兩階段Gr。

In this study, the Schlieren method was used to investigate the mechanism of soot formation of Bio-oil. The characteristics of liquid fuel influence the characteristics of spray combustion or droplet combustion. These characteristics include: Component, saturated vapor pressure, boiling point, flash point and viscosity coefficient, etc. The viscosity of the fuel affects the quality of the spray and the characteristics of liquid fuel’s components affect the characteristics of fuel evaporation, flash ignition and combustion transfer. When the use of raw energy instead of fossil fuels become an important issue. The pyrolytic Bio-oil of the raw material is produced by the thermal decomposition of cellulose raw materials, but the components of the Bio-oil are quite complex. It is related to the source of its material and the parameters of the pyrolysis program. And there are many problems in use, including soot, coking, corrosion, etc. In GC-MS, TGA and FT-IR results show that the pyrolysis Bio-oil is mainly composed of polycyclic compounds, including: alkanes, aromatic hydrocarbons, phenols and aldehydes, etc. These components are precursor for soot formation and the boiling point of the volatiles of the bio-oil component during the combustion process, the difference in flash point (mainly polycyclic compounds such as aromatic hydrocarbons, alkanes, phenols and aldehydes) and the formation of particles, Different stages of droplet burning rate are formed. The direct image observation of the droplet combustion, When the Bio-oil droplets burned, droplet flame surround the entire droplet and the combustion process occurs once and twice micro-explosion. Under the normal gravity, it is affected by buoyancy and natural convection, so that the soot which surrounding the combustion droplet are blown away and during droplet combustion, is not easily observed by the visible image. So using the synchronous tech with dual-high camera and schlieren method can clearly observe the droplet combustion, and with the change in density under the flow field and diffusion during the droplet combustion. The result show that soot are formed in the shape of a chimney (called soot tail) and are distributed inside the visible flame, while the hot gas boundary is located outside the visible flame. The stagnation plane called Stefan flow which formed by the chemical interaction between the fuel and the oxidant and the reaction is surrounded by the lower circle of the combustion droplet. In the other hand, the soot tail affects the heat transfer from the flame to the droplet surface and the soot with it radiates to promote heat exchange, which shows the temperature tends to be unstable and the slope increases significantly of surface boiling point from the fast pyrolysis droplets. As the combustion process evolves, more weaker carbon bond components participate into the reaction, which influenced by the composition and the soot tail. And the significant soot formation effect the Grashof number with different stages of the density change.

摘要..........i
Abstract..........iv
誌謝..........vi
目錄..........vii
表目錄..........x
圖目錄..........xi
符號說明..........xiii
第一章 前言..........1
1.1工業應用..........1
1.1.1內燃機..........1
1.1.2燃燒鍋爐..........2
1.2液態燃料燃燒..........2
1.2.1霧化及液滴產生機制..........5
1.2.2液滴燃燒..........7
1.3石化燃料..........8
1.3.1石油..........9
1.3.2煤油..........9
1.4生質燃料..........10
1.4.1生質柴油..........12
1.4.2熱裂解生質油..........12
1.5研究目標..........13
第二章 文獻回顧..........15
2.1噴霧燃燒..........15
2.1.1 燃料特性..........15
2.1.2 霧化器噴嘴..........18
2.1.3 操作環境..........19
2.2混合燃料霧化及燃燒..........21
2.3液滴燃燒理論..........21
2.3.1多組份液滴燃燒..........23
2.3.2液滴微爆..........24
2.3.3液滴燃燒微粒生成..........26
2.4燃料微粒形成機制..........27
第三章 實驗方法..........30
3.1裂解生質油製備..........30
3.1.1快速裂解產油設備..........30
3.1.2慢速裂解產油設備..........31
3.2生質油化學組成與熱分析..........32
3.2.1氣相層析質譜法(GC-MS)..........32
3.2.2熱重分析(Thermogravimetric analysis)..........33
3.2.3傅立葉紅外光譜(Fourier Transform Infrared Spectroscopy)..........34
3.3液滴燃燒實驗..........35
3.3.1背光成像..........35
3.3.2紋影成像(schlieren)..........36
3.3.3液滴懸掛..........40
3.3.4觀測設備..........41
3.3.5溫度量測設備..........42
3.4實驗步驟..........43
第四章 結果與討論..........45
4.1裂解生質油燃料特性..........45
4.1.1 熱裂解生質油化學組成..........45
4.1.2 熱裂解生質油熱分析..........47
4.1.3小結..........51
4.2燃燒液滴火焰結構..........52
4.2.1燃燒液滴直接影像觀測..........52
4.2.2燃燒液滴紋影成像..........55
4.2.3燃燒液滴火焰結構..........60
4.2.4小結..........63
4.3生質油液滴熱傳..........64
4.3.1生質油液滴火焰溫度量測..........64
4.3.2生質油燃燒活化能..........65
4.3.3生質油液滴表面溫度..........67
4.4生質油液滴燃燒速率..........68
4.4.1背光法觀測燃燒生質油液滴表面現象..........68
4.4.2生質油液滴燃燒速率..........70
4.4.3浮力效應..........73
4.4.4小結..........74
第五章 實驗結論..........75
第六章 未來工作..........78
參考文獻..........79
Extended Abstract..........84

[1]Saat, A. Fundamental Studies of Combustion of Droplet and Vapour Mixtures. PhD thesis,2010.
[2]Beer, J. M. & Chigier, N.A. Combustion Aerodynamics. New York. Applied Science Publishers,1972.
[3]Baumgarten, C. Mixture formation in internal combustion engines. Springer Science & Business Media,2006.
[4]Renewables 2018 Global Status Report.
[5]Onuma, Y., & Ogasawara, M. Studies on the structure of a spray combustion flame. In Symposium (International) on Combustion. Vol.15,453-465,1975.
[6]Demirbas, A. Combustion characteristics of different biomass fuels Prog. Progress in Energy and Combustion Science. Vol.30,219-230,2004.
[7]Solmaz, H. Combustion, performance and emission characteristics of fusel oil in a spark ignition engine. Fuel Processing Technology. Vol.133, 20-28,2015.
[8]Awad, O. I., Mamat, R., Ali, O. M., Yusri, I. M., Abdullah, A. A., Yusop, A. F., & Noor, M. M. The Effect of Adding Fusel Oil to Diesel on the Performance and the Emissions characteristics in a Single Cylinder CI engine. Energy Institute. Vol.90,382-396,2017.
[9]Wang, C., Xu, H., Daniel, R., Ghafourian, A., Herreros, J. M., Shuai, S., & Ma, X. Combustion characteristics and emissions of 2-methylfuran compared to 2, 5-dimethylfuran, gasoline and ethanol in a DISI engine. Fuel. Vol.103,200-211, 2013.
[10]Farrell JT, Cernansky NP, Dryer FL. Development of an experimental database and kinetic models for surrogate diesel fuels. SAE Technical Paper.No 2007-01-0201,2007.
[11]Jahani, H., & Gollahalli, S. R. Characteristics of Burning Jet A Fuel and Jet A Fuel Water Emulsion Spray. Combustion and Flame. Vol.37,145-154,1980.
[12]Payri R, Salvador FJ, Gimeno J, Bracho G. Understanding diesel injection characteristics in winter conditions. SAE Paper. No 2009-01-0836.
[13]McDonell, V. G., & Samuelsen, S. Gas and Drop Behavior in Reacting and Non-Reacting Airblast Atomizer Sprays. Propulsion and Power. Vol.7, 684-691,1991.
[14]Faeth, G. M., Hsiang, L.P., and Wu, P.K.. Structure and Break-up Properties of Spray.Multiphase Flow. Vol.21,99-127,1995.
[15]Yang, S. I., Wu, M. S., & Hsu, T. C. Spray combustion characteristics of kerosene/bio-oil part I:Experimental study. Energy. Vol.119,26-36, 2017.
[16]Wu, M. S., & Yang, S. I. Combustion characteristics of multi-component cedar bio-oil/kerosene droplet. Energy. Vol.115,788-795, 2016.
[17]Yi, F., & Axelbaum, R. L. Stability of spray combustion for water/alcohols mixtures in oxygen-enriched air. Proceedings of the Combustion Institute. Vol.34,1697-1704,2013
[18]Iyer, V. A., Abraham, J., & Magi, V. Exploring Injected Droplet Size Effects on Steady Liquid Penetration in a Diesel Spray with a Two-Fluid Model. Heat and Mass Transfer. Vol.45,519-531,2002.
[19]Komada, K., Sakaguchi, D., Tajima, H., Ueki, H., & Ishida, M. Relation between Tip Penetration and Droplet Size of Diesel Spray. SAE Technical Paper No. 2013-01-1599,2013.
[20]Bohl T, Tian G, Smallbone A, Roskilly AP. Macroscopic spray characteristics of next-generation bio-derived diesel fuels in comparison to mineral diesel. Applied Energy. Vol.186, 562-573,2017.
[21]Sarv, H., Nizami, A. A., Cernansky, N.P. Droplet Size Effects on NOx Formation in a One-Dimensional Monodisperse Spray Combustion System. Joint Power Generation Conference: GT Papers, The American Society of Mechanical Engineers (ASME); 1982.
[22]Hiroyasu, H., & Kadota, T. Fuel droplet size distribution in diesel combustion chamber. SAE Transactions, 2615-2624. 1974.
[23]Ambekar, A., Chowdhury, A., Challa, S., & Radhakrishna, D. Droplet Combustion Studies of Hydrocarbon-Monopropellant Blends. Fuel. Vol.115, 697–705,2014.
[24]Yu, Y., Li, M., Zhou, Y., Lu, X., & Pan, Y. Study on electrical ignition and micro-explosion properties of HAN-based monopropellant droplet. Frontiers of Energy and Power Engineering in China.Vol.3, 430-435,2010.
[25]Wei, J. B., & Shaw, B. D. Influences of Pressure on Reduced-Gravity Combustion of HAN-Methanol-Water Droplets in Air. Combustion and Flame. Vol.146,484-492,2006.
[26]Tarifa, C. S. On the influence of chemical kinetics on the combustion of fuel droplets. NATIONAL INST FOR AEROSPACE TECHNOLOGY MADRID (SPAIN),1962.
[27]Goldsmith, M. On the burning of single drops of fuel in an oxidizing atmosphere. Jet Propulsion .Vol.24,245-251,1954.
[28]Goldsmith, M. Experiments on the burning of single drops of fuel. Jet Propulsion .Vol.26,172-178,1956.
[29]Kumagai, S., T. Sakai, and S. Okajima. Combustion of free fuel droplets in a freely falling chamber. Symposium (International) on Combustion. Vol.13,779-785,1971.
[30]Monaghan, M. T., Siddall, R. G., & Thring, M. W. The influence of initial diameter on the combustion of single drops of liquid fuel. Combustion and Flame. Vol.12,45-53,1968.
[31]Spalding, D.B. The Combustion of Liquid Fuels. Symposium (international) on combustion. Vol.4,847-864,1953.
[32]Ross, H. D. Microgravity combustion: fire in free fall. Elsevier.2001.
[33]Law, C.K. Recent Advances in Droplet Vaporization and Combustion. Progress in Energy and Combustion Science. Vol.8, 171-201,1982.
[34]Wang, C. H., Liu, X. Q., Law, C.K. Combustion and Microexplosion of Freely Falling Multicomponent Droplets. Combustion and Flame. Vol.56,175-197,1984.
[35]Siringnano, W.A. Fluid Dynamics and Transport of Droplets and Sprays. 2nd Editio. Cambridge University Press. 2010.
[36]Wood, B. J., Wise, H., Inami, S.H. Heterogeneous Combustion of Multicomponent Fuels. Combustion and Flame. Vol.4, 235-242, 1960.
[37]Watanabe, H., Harada, T., Matsushita, Y., Aoki, H., Miura, T. The Characteristics of Puffing of the Carbonated Emulsified Fuel. Heat and Mass Transfer. Vol.52, 3676-3684,2009.
[38]Lasheras, J. C., Fernandez-Pello, A. C., Dryer, F.L. Experimental Observations on the Disruptive Combustion of Free Droplets of Multicomponent Fuels. Combustion Science and Technology. Vol.22, 195-209, 1980.
[39]Lasheras, J. C., Fernandez-Pello, A. C., Dryer, F.L. On the Disruptive Burning of Free Droplets of Alcohol/n-Paraffin Solutions and Emulsions. Symposium (international) on combustion. Vol.18, 293-305,1981.
[40]Yap, L. T., Kennedy, I. M., & Dryer, F. L. Disruptive and Micro-Explosive Combustion of Free Droplets in Highly Convective Environments. Combustion Science and Technology. Vol.41,291-313,1984.
[41]Watanabe, H., Suzuki, Y., Harada, T., Matsushita, Y., Aoki, H., Miura, T. An Experimental Investigation Of The Breakup Characteristics Of Secondary Atomization Of Emulsified Fuel Droplet. Energy. Vol.35, 806-813,2010.
[42]Shinjo, J., Xia, J., Ganippa, L.C., Megaritis, A. Physics of Puffing and Microexplosion of Emulsion Fuel Droplets. Physics of Fluids.Vol.26,103302,2014.
[43]Shinjo, J., Xia, J., Ganippa, L. C., Megaritis, A. Puffing-Enhanced Fuel/Air Mixing of an Evaporating n-Decane/Ethanol Emulsion Droplet and a Droplet Group under convective heating. Fluid Mechanics. Vol.793, 444-476,2016.
[44]Shinjo, J., Xia, J. Combustion Characteristics of a Single Decane/Ethanol Emulsion Droplet and a Droplet Group under Puffing Conditions. Proceedings of the Combustion Institute. Vol.36, 2513-2521,2017.
[45]Hara, H., & Kumagai, S. Experimental investigation of free droplet combustion under microgravity. Symposium (International) on Combustion. Vol.23, 1605-1611, 1990.
[46]Choi, M. Y., & Haggard Jr, J. B. Observations on a slow burning regime for hydrocarbon droplets : n-heptaneiair results. Symposium (International) on Combustion. Vol.23,1597-1604,1990.
[47]Yang, J. C., Jackson, G. S., & Avedisian, C. T. Some experiments on free droplet combustion at low gravity. AIP Conference Proceedings. Vol.197, 394 403,1990.
[48]Pan, K. L., Li, J. W., Chen, C. P., & Wang, C. H. On droplet combustion of biodiesel fuel mixed with diesel-alkanes in microgravity condition. Combustion and Flame. Vol.156,1926-1936, 2009.
[49]Prado, G., & Lahaye, J. Mechanisms of PAH Formation and Destruction in Flames Relation to Organic Particulate Emissions. Mobile Source Emissions Including Policyclic Organic Species. Vol.112,259-275,1983.
[50]Siegla, D. Particulate carbon formation during combustion. Springer Science & Business Media,1981.
[51]Haynes, B. S., & Wagner, H. G. The surface growth phenomenon in soot formation. Zeitschrift für Physikalische Chemie. Vol.133,201-213,1982.
[52]Bockhorn H, editor. Soot formation in combustion: mechanisms and models. Berlin: Springer, 1994.
[53]Yang, S. I., Wu, M. S., Wu, C. Y. Application of biomass fast pyrolysis part I: Pyrolysis characteristics and products. Energy, Vol. 66,162-171,2014.
[54]Yang, S. I., & Wu, M. S. The droplet combustion and thermal characteristics of pinewood bio-oil from slow pyrolysis. Energy. Vol.141, 2377-2386,2017.
[55]Degen, N. An overview on Schlieren optics and its applications Studies on mechatronics. 2012.
[56]Yu, F., & Shaw, B. D. Interpretation of backlit droplet images from ISS droplet combustion experiments. Gravitational and Space Research. Vol.2,2014.
[57]Sakamoto, H., & Kulacki, F. A. Buoyancy-driven flow in fluid-saturated porous media near a bounding surface.
[58]Griffiths, J. F., & Barnard, J. A. Flame and combustion. CRC Press.1995.
[59]吳敏聖.生質油混合丁醇之化學動力機制與液滴燃燒特性,博士論文,國立虎尾科技大學,2018.
[60]Ogami, Y., Sakurai, S., Hasegawa, S., Jangi, M., Nakamura, H., Yoshinaga, K., & Kobayashi, H. Microgravity experiments of single droplet combustion in oscillatory flow at elevated pressure. Proceedings of the Combustion Institute. Vol.32,2171-2178,2009.