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J4  2011, Vol. 45 Issue (1): 146-150    DOI: 10.3785/j.issn.1008-973X.2011.01.025
    
Effect of external wind temperature to micro-scale flame
ZHOU Jun-hu, WANG Yang, YANG Wei-juan, LIU Jian-zhong, WANG Zhi-hua, CEN Ke-fa
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
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Abstract  

The surface heat loss of a micro combustor was controlled by the external wind temperature and the performances of the combustor under different wind temperatures were compared in order to analyze the stability of micro combustor affected by the  heat loss. The flow rates of fuel mixture were 0.12, 0.24, 0.36 L/min. The wind temperatures were adjusted to 277.15, 380.15, 635.15, 790.15 and 1 001.15 K. Experimental results show that increasing the wind temperature or fuel-mixture flow rate can inhibit the extinction.   The surface temperatures of the combustor at different conditions were measured. The numerical simulation was applied to investigate the internal combustion process. Results showed that the higher wind temperature made the reaction temperature increase and the reaction region shift upstream. At 0.24 L/min and stoichiometric condition, the peak temperature increased by 165 K and the reaction region shifted upstream by 5 mm while the wind temperature increased from 277.15 K to 1001.15 K. Accordingly, high wind temperature intensifies the reaction rate, thus inhibites extinction. The heat loss increased while the flow rate increased from 0.12 to 0.36 L/min. But the ratio of heat loss to total energy decreased, which indicated that increasing fuel-mixture flow rate can inhibit extinction.



Published: 03 March 2011
CLC:  TK 16  
Cite this article:

ZHOU Jun-hu, WANG Yang, YANG Wei-juan, LIU Jian-zhong, WANG Zhi-hua, CEN Ke-fa. Effect of external wind temperature to micro-scale flame. J4, 2011, 45(1): 146-150.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2011.01.025     OR     http://www.zjujournals.com/eng/Y2011/V45/I1/146


不同外部风温对微尺度火焰的影响

为了研究微尺度燃烧器由于散热造成燃烧稳定性差的问题,对微尺度燃烧器外部吹风控制表面散热,对比不同工况下燃烧器的工作性能.当燃料混合气体体积流量为0.12、0.24、0.36 L/min时,风温分别为277.15、380.15、635.15、790.15、1 001.15 K.实验结果表明,提高冷却风温或燃料流量可以抑制熄火.测量燃烧器壁面温度,结合数值模拟,研究内部燃烧过程.结果显示,随着冷却风温上升,反应区域峰值温度上升且向上游偏移.在024 L/min,燃料气体当量配比下,当冷却风温由277.15 K上升到1 001.15 K时,峰值温度上升约165 K,反应中心上移约5 mm.证明高温冷却风通过减少散热,提升反应强度,抑制热熄火.当体积流量由0.12 L/min上升到0.36 L/min时,虽然壁面散热量上升,但占总能量的份额相对降低,因此提升燃料流量可以抑制热熄火.

[1] AHN J, EASTWOOD C, SITZKI L, et al. Gasphase and catalytic combustion in heatrecirculating burners [J]. Proceedings of the Combustion Institute, 2005, 30(2): 2463-2472.
[2] FERNANDEZPELLO C. Micropower generation using combustion: Issues and approaches [J]. Proceedings of the Combustion Institute, 2002. 29(1): 883-899.
[3] JACOBSON S A, EPSTEIN A.H. An informal survey of power mems [C]∥The International Symposium on MicroMechanical Engineering. Tsukuba, Japan:[s. n.],2003.
[4] SPADACCINI C M, MEHRA A, LEE J. High power density silicon combustion system for micro gas turbine engines [J]. Engineering Gas Turbines Power, 2003, 9(4): 517-527.
[5] EPSTEIN A H, SENTURIA S D, ANATHASURESH G. Power mems and microengines [C]∥IEEE Transducers 97 Conference. Chicago: IEEE, 1997.
[6] YANG W M, CHOU S K, SHU C, et al. Microscale combustion research for application to micro thermophotovoltaic systems [J]. Energy Conversion and Management, 2003, 44(16): 2625-2634.
[7] CHIA L C, FENG B. The development of a micropower (microthermophotovoltaic) device [J]. Journal of Power Sources, 2007, 165(1): 455-480.
[8] YUASA S, OSHIMI K, NOSE H, et al. Concept and combustion characteristics of ultramicro combustors with premixed flame [J]. Proceedings of the Combustion Institute, 2005, 30(2): 2455-2462.
[9] WAITZ I A, GAUBA G, TZENG Y S T. Combustors for microgas turbine engines [J]. American Society of Mechanical Engineers, 1998, 120: 109-117.
[10] CHURCHILL S W. Thermally stabilized combustion [J]. Chemical Engineering and Technology, 1989, 12(1): 249-254.
[11] LEACH T T, CADOU C P. The role of structural heat exchange and heat loss in the design of efficient silicon microcombustors [J]. Proceedings of the Combustion Institute, 2005, 30(2): 2437-2444.

[12] HUA J, WU M, KUMAR K. Numerical simulation of the combustion of hydrogenair mixture in microscaled chambers part ii: CFD analysis for a microcombustor [J]. Chemical Engineering Science, 2005, 60(13): 3507-3515.
[13] NORTON D G, VLACHOS D G. A CFD study of propane/air microflame stability [J]. Combustion and Flame, 2004, 138(1/2): 97-107.
[14] NORTON D G, VLACHOS D G. Combustion characteristics and flame stability at the microscale: a CFD study of premixed methane/air mixtures [J]. Chemical Engineering Science, 2003, 58(21): 4871-4882.
[15] LLOYD S A, WEINBERG F J. Limits to energy release and utilization from chemical fuels [J]. Nature, 1974, 251: 47-49.
[16] KAISARE N S, DESHMUKH S R, VLACHOS D G. Stability and performance of catalytic microreactors: simulations of propane catalytic combustion on pt [J]. Chemical Engineering Science, 2008, 63(4): 1098-1116.
[17] RONNEY P D. Analysis of nonadiabatic heatrecirculating combustors [J]. Combustion and Flame, 2003, 135(4): 421-439.
[18] VICAN J, GAJDECZKO B F,  DRYER F L, et al. Development of a microreactor as a thermal source for microelectromechanical systems power generation [J]. Proceedings of the Combustion Institute, 2002, 29: 909-916.
[19] BOYARKO G A, SUNG C J, SCHNEIDER S J. Catalyzed combustion of hydrogenoxygen in platinum tubes for micropropulsion applications [J]. Proceedings of the Combustion Institute, 2005, 30(2): 2481-2488.
[20] HOLLADAY J D, JONES E O, PHELPS M, et al. Microfuel processor for use in a miniature power supply [J]. Journal of Power Sources, 2002, 108(1/2): 21-27.
[21] JEONGMIN A, CRAIG E, LARS S, et al. Gasphase and catalytic combustion in heatrecirculating burners [J]. Proceedings of the Combustion Institute, 2005, 30(2): 2463-2472.
[22] MASEL R I, SHANNON M. Microcombustor having submillimeter critical dimensions [C]∥The Board of Trustees of the University of Illinois. Urbana: [s. n.], 2001.
[23] POINSOT T, CANDEL S, TROUV A. Applications of direct numerical simulation to premixed turbulent combustion [J]. Progress in Energy and Combustion Science, 1995, 21(6): 531-576.
[24] KIM N I, KATO S, KATAOKA T, et al. Flame stabilization and emission of small swissroll combustors as heaters [J]. Combustion and Flame, 2005, 141(3): 229-240.
[25] BARRA A J, ELLZEY J L. Heat recirculation and heat transfer in porous burners [J]. Combustion and Flame, 2004, 137(1/2): 230-241.
[26] CHEN GB, CHAO YC, CHEN CP. Enhancement of hydrogen reaction in a microchannel by catalyst segmentation [J]. International Journal of Hydrogen Energy, 2008, 33(10): 2586-2595.
[27] CHEN G B, CHEN C P, WU C Y, et al. Effects of catalytic walls on hydrogen/air combustion inside a microtube [J]. Applied Catalysis A: General, 2007, 332(1): 89-97.

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