تشخیص ناپایداری شعله در مشعل پیش آمیخته شعله سطحی با استفاده از تحلیل فرکانسی

بدرخواهان, محمدهادی; ضابطیان طرقی, محمد; کرفی, محمدرضا

doi:10.22034/jfnc.2020.106253

تشخیص ناپایداری شعله در مشعل پیش آمیخته شعله سطحی با استفاده از تحلیل فرکانسی

نوع مقاله : مقاله پژوهشی

نویسندگان

¹ تربیت مدرس فارغ التحصیل رشته مهندسی مکانیک

² تربیت مدرس مهندسی مکانیک

10.22034/jfnc.2020.106253

چکیده

در این پژوهش، با استفاده از حسگر نوری و سیستم داده برداری، به بررسی پایداری مشعل شعله سطحی پرداخته می شود. نوسانات شدت نور توسط حسگر نوری اندازه گیری و سپس، با استفاده از تبدیل فوریه سریع، از فضای زمانی به فضای فرکانسی انتقال داده شد و از منحنی پاسخ فرکانسی، فرکانس طبیعی نوسانات استخراج شد. برای اینکه بتوانیم رفتار دینامیک را برای شعله پیش آمیخته نشان دهیم، شعله های پیش آمیخته به دو ناحیه شعله های سلولی و شعله های مسطح تقسیم بندی می شوند. این تقسیم بندی وابسته به نرخ جریان و نسبت هم ارزی است. در شعله های مسطح، با افزایش نرخ جریان، بهدلیل افزایش سرعت گازهای داغ سوخته شده، فرکانس نوسانات نیز افزایش می یابد. در شعلهه ای سلولی، با افزایش نرخ جریان، فرکانس نوسانات کاهش پیدا می کند. در نرخ های جریان یکسان، کاهش شدید فرکانس نوسانات نشان دهنده ظهور شعله های سلولی است. بنابراین، امکان تشخیص گذر شعله از حالت مسطح به سلولی فراهم می شود.زمانی که در یک نرخ جریان ثابت، با افزایش نسبت هم ارزی، شاهد افزایش فرکانس نوسانات نباشیم، انتقال از شعله سلولی به شعله مسطح اتفاق می افتد. شروع انتقال از شعله سلولی به شعله مسطح در نرخ های جریان 1/1، 1/2، 1/3، 1/4، 1/5 و 1/6 مترمکعب بر ساعت به ترتیب در نسبت های هم ارزی 0/6، 0/62، 0/62، 0/64، 0/66 و 0/67 اتفاق می افتد. محل شروع انتقال منطبق بر شروع ناحیه برخاستگی براساس پردازش تصویر است. این پژوهش، دارای جنبه های تازهای از بررسی پایداری شعله می باشد بدون آنکه سبب اختلال در شکل شعله شود و به رژیم شعله آسیب وارد کند.

کلیدواژه‌ها

موضوعات

تحلیل شعله ها (پیش آمیخته و غیر پیش آمیخته)

عنوان مقاله [English]

Diagnostics of flame instability in a premixed surface flame burner using frequency analysis

نویسنده [English]

Mohammad Zabetian Targhi ²

² Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

چکیده [English]

This study investigates the stability of a surface flame burner using a photodiode and data acquisition system. The light intensity fluctuations were measured by the photodiode and, using fast Fourier transform, they were transferred from the temporal to the frequency space. To illustrate the dynamic behavior of premixed flames, flames are divided into two regions of cellular flames and surface flames. This classification is dependent on the flow rate and the equivalence ratio. In surface flames, as the flow rate increases, the oscillation frequency also increases because the hot burned gas velocity increases. In cellular flames, as the flow rate increases, oscillation frequency decreases. At identical flow rates, the sharp decrease in the oscillation frequency indicates the appearance of cellular flames so we can find the transition from the surface flame to the cellular flame. At a constant flow rate, with an increase in the equivalence ratio, there is no increase in the oscillation frequency, the transition from the cellular flame to the surface flame occurs. The initiation of the transition from the cellular flame to the surface flame occurs at flow rates of 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 m3 / h and at equivalence ratios of 0.6 , 0.62, 0.62, 0.64, 0.66, and 0.67, respectively. The location of the transition corresponds to the start of the liftoff zone based on image processing. This research is innovative because it is possible to evaluate flame stability using a non-intrusive method without disturbing the flame shape and damaging the flame regime.

کلیدواژه‌ها [English]

Intrinsic Instability
Cellular Flame
planar Flame
Typical-oscillation frequency
Frequency Analysis

مراجع

1. J. W. Robinson, Practical handbook of spectroscopy, CRC Press, Routledge, 2017.
2. M., el-HAMDI, M. Gorman and K. A. Robbins, "Deterministic chaos in laminar premixed flames: Experimental classification of chaotic dynamics," Combustion science and technology, 94, No. 1–6, 1993, pp. 87–101.
3. M. Izumikawa, T. Mitani and T. Niioka, "Experimental study on cellular flame propagation of blend fuels," Combustion and flame, 73, No. 2, 1988, pp. 207–214.
4. F. Williams, Combustion Theory, Redwood City, Addison-Wesley, 2’nd Edition, CA, 1985,.
5. C. Clanet and G. Searby, "First experimental study of the Darrieus-Landau instability," Physical review letters, 80, No. 17, 1998, pp. 3867-3870.
6. P. Clavin, "Dynamic behavior of premixed flame fronts in laminar and turbulent flows," Progress in energy and combustion science, 11, No. 1, 1985, pp. 1–59.
7. S. Kadowaki, "Instability of a deflagration wave propagating with finite Mach number," Physics of Fluids, 7, No. 1, 1995, pp. 220–222.
8. X. Qin, H. Kobayashi and T. Niioka, "Laminar burning velocity of hydrogen–air premixed flames at elevated pressure," Experimental Thermal and Fluid Science, 21, No. 1–3, 2000, pp. 58–63.
9. G. I. Sivashinsky, "Instabilities, pattern formation, and turbulence in flames," Annual Review of Fluid Mechanics, 15, No.1, 1983, pp. 179–199.
10. H. Gotoda and T. Ueda, "Transition from periodic to non-periodic motion of a bunsen-type premixed flame tip with burner rotation," Proceedings of the Combustion Institute, 29, No. 2, 2002, pp. 1503–1509.
11. H. Gotoda and T. Ueda, "Orbital instability and prediction of a Bunsen flame tip motion with burner rotation," Combustion and flame, 140, No. 4, 2005 , pp. 287–298.
12. F. Takens, "Detecting strange attractors in turbulence," Lecture notes in mathematics, 898, No. 1, 1981, pp. 366–381.
13. A. Kaewpradap and S. Kadowaki, "Heat-loss effects on the chaotic behavior of cellular premixed flames generated by intrinsic instability," Journal of Thermal Science and Technology, 2, No. 1, 2007, pp. 79–89.
14. S. Kadowaki and N. Ohkura, "Time series analysis on the emission of light from methane-air lean premixed flames: diagnostics of the flame Instability," Transactions of the Japan Society for Aeronautical and Space Sciences, 51, No. 173, 2008, pp. 133–138.
15. S. Lee, S. M. Kum and C.-E. Lee, "An experimental study of a cylindrical multi-hole premixed burner for the development of a condensing gas boiler," Energy, 36, No. 7, 2011, pp. 4150–4157.
16. R. R. John and M. Summerfield, "Studies of the mechanism of flame stabilization by a spectral intensity method," Jet Propulsion, 25, 1955, pp. 535-540.
17. R. R. John and M. Summerfield, "Effect of turbulence on radiation intensity from propane-air flames," Jet Propulsion, 27, 1957, pp. 224-230.
18. I. Hurle and et al. "Sound emission from open turbulent premixed flames," in Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 1968. The Royal Society.
19. A. Kaewpradap and S. Jugjai, "Effects of CH4 and CO2 on Intrinsic Instability of Synthetic Thai Natural Gas Flames," The 7th TSME International Conference on Mechanical Engineering, Chiang Mai, Thailand, 2016.
20. A. Kaewpradap and S. Kadowaki, "Instability Influenced by CO2 and Equivalence Ratio in Oxyhydrogen Flames on Flat Burner," Combustion Science and Technology, 189, No. 3, 2017, pp. 438–452.
21. W. Kim et al., "Wrinkling of Large-Scale Flame in Lean Propane–Air Mixture Due to Cellular Instabilities," Combustion Science and Technology, 191, No. 3, 2019, pp. 491–503.
22. F. Schiro and A. Stoppato, "Experimental investigation of emissions and flame stability for steel and metal fiber cylindrical premixed burners," Combustion Science and Technology, 191, No. 3, 2019, pp. 453–471.
23. S. R. Turns, An introduction to combustion, New York, McGraw-hill, Vol. 287. 1996.
24. M. Najarniku, Experimental analysis of a premixed perforated burner used in condensing boilers, Ms Thesis, Department of Mechanical Engineering, Tarbiat Modares University, 2018. (in Persian)
25. W. Gonzalez and R. E. Woods, Eddins, Digital Image Processing using MATLAB, Third New Jersey, Prentice Hall, 2004.
26. H. W. Huang and Y. Zhang, "Flame colour characterization in the visible and infrared spectrum using a digital camera and image processing," Measurement Science and Technology, 19, No. 8, 2008, pp. 1-9.
27. G. Joulin and P. Clavin, "Linear stability analysis of nonadiabatic flames: diffusional-thermal model," Combustion and Flame, 35, 1979, pp. 139–153.
28. S. Sohrab and B. Chao, "Influences of upstream versus downstream heat loss/gain on stability of premixed flames," Combustion Science and Technology, 38, No. 5–6, 1984, pp. 245–265.
29. S. Kadowaki "The effects of heat loss on the burning velocity of cellular premixed flames generated by hydrodynamic and diffusive-thermal instabilities," Combustion and Flame, 143, No. 3, 2005, pp. 174–182.
30. H. Soltanian, M. Z. Targhi and H. Pasdarshahri, "Chemiluminescence usage in finding optimum operating range of multi-hole burners," Energy, 180, 2019, pp. 398–404.