مطالعه عددی تاثیر سینتیک شیمیایی و مدل تشعشعی بر میدان دما و سرعت در احتراق گاز طبیعی- اکسیژن با استفاده از مدل احتراقی فلیملت پایا

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی مکانیک دانشگاه تربیت مدرس

2 دانشگاه تربیت مدرس

3 دانشجوی دکتری دانشگاه تربیت مدرس

چکیده

هدف مطالعه حاضر بررسی تاثیر سینتیک شیمیایی و مدل تشعشعی در شبیه‌سازی احتراق گاز طبیعی- اکسیژن با استفاده از مدل احتراقی فلیملت است. بدین منظور از سه سینتیک شیمیایی C1_C3، DRM22 و GRI3.0 جهت بررسی سینتیکی و از دو مدل تشعشعی DO و P1 به‌منظور بررسی تاثیر مدل تشعشعی استفاده شده است. همچنین نتایج حاصل از در نظر گرفتن انتقال حرارت تشعشعی با شرایط بدون تشعشع نیز مقایسه شده است. نتایج حاصل از مدل فلیملت با داده‌های تجربی و مدل احتراقی PaSR مقایسه شده‌اند. مهمترین مزیت استفاده از مدل احتراقی flamelet نسبت به مدل PaSR کاهش قابل توجه هزینه‌ محاسبات است. مطابق یا نتایج بدست آمده، سینتیک C1_C3 بالاترین دقت را در پیش‌بینی توزیع دمای داخل کوره داشته و شعله ایجاد شده به وسیله آن تطابق خوبی با شبیه‌سازی انجام شده به وسیله مدل احتراقی PaSR دارد؛ در حالی که طول شعله حاصل از سینتیک‌های DRM22 و GRI3.0 بسیار کم پیش‌بینی شده است. علاوه‌بر این استفاده از مدل تشعشعی P1 در مقایسه با مدل DO به علت پیش‌بینی بیشتر مقادیر تلفات تشعشعی در آن منجر به خطای محاسباتی بیشتر در محاسبه توزیع دما و همچنین پیش‌بینی طول ناحیه دما بالا درون کوره می‌شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Study of Chemical Kinetic and Radiation Model Effects on the Velocity and Temperature Fields in Natural Gas- Oxygen Combustion by Using of Steady Flamelet Model

نویسندگان [English]

  • Kiumars Mazaheri 2
  • Faeze Ehsani Derakhshan 3
2 Tarbiat Modares University
3 Tarbiat Modares University
چکیده [English]

The aim of this study was to investigate the effect of chemical kinetics and radiation model on the simulation of natural gas- oxygen combustion by using flamelet combustion model. For this purpose, C1_C3, DRM22 and GRI3.0 chemical kinetics in order to kinetically investigation and the radiation model effect has been used from two radiation model DO and P1. Also, results from the consideration of radiation heat transfer with non-radiation conditions are compared. The results of flamelet combustion model have been compared with the experimental data and PaSR combustion model. The most important advantage of using flamelet combustion model over the PaSR model is a significant reduction in the cost of calculation. According to obtained results, C1_C3 chemical mechanism predicting temperature distribution in furnace with highest accuracy and flame shape created by it has good match with PaSR model simulation; While the obtained flame length with DRM22 and GRI3.0 chemical mechanisms predicted very low. In addition, the use of P1 radiation model in comparison with DO model due to prediction of higher radiation losses in it leads to more computational errors in calculating the temperature distribution as well as the prediction of the length of the high temperature region in furnace.

کلیدواژه‌ها [English]

  • Natural Gas- Oxygen Combustion
  • Flamelet Combustion Model
  • Radiation Model
  • Chemical Kinetic
1.   M. M. Maroto-Valer, Developments and Innovation in Carbon Dioxide (CO2) Capture and Storage Technology: Carbon Dioxide (CO2) Storage and Utilisation, Elsevier, Amesterdam, 2010.
2.    C. E. Baukal Jr, Oxygen-enhanced combustion, CRC press, New York, 2010.
3.    M. Kanniche and et al., Pre-combustion, post-combustion and oxy-combustion in thermal power plant for CO 2 capture, Applied Thermal Engineering, 30, No. 1, 2010, pp. 53-62.
4.    A. A. Bhuiyan, and J. Naser, Numerical modelling of oxy fuel combustion, the effect of radiative and convective heat transfer and burnout, Fuel, 139, 2015, pp. 268-284.
5.    B. Mayr and et al., CFD and experimental analysis of a 115kW natural gas fired lab-scale furnace under oxy-fuel and air-fuel conditions, Fuel, 159, 2015, pp. 864-875.
6.    J. Andersen and et al., Global combustion mechanisms for use in CFD modeling under oxy-fuel conditions, Energy & Fuels, 23, 3, 2009, pp. 1379-1389.
7.    C. Yin, L. A. Rosendahl and S. K. Kær, Chemistry and radiation in oxy-fuel combustion: a computational fluid dynamics modeling study, Fuel, 90, No. 7, 2011, pp. 2519-2529.
8.    C. Yin, Nongray-gas effects in modeling of large-scale oxy–fuel combustion processes, Energy & Fuels, 26, No. 6, 2012, pp. 3349-3356.
9.    C. Yin and et al., New weighted sum of gray gases model applicable to computationalfluid dynamics (CFD) modeling of oxy-fuel combustion: derivation, validation, and implementation, Energy & Fuels, 24, No. 12, 2010, pp. 6275-6282.
10.  T. Smith, Z. Shen and J. Friedman, Evaluation of coefficients for the weighted sum of gray gases model, Journal of Heat Transfer, 104, No. 4, 1982, pp. 602-608.
11.  Z. Wheaton and et al., A comparative study of gray and non-gray methods of computing gas absorption coefficients and its effect on the numerical predictions of oxy-fuel combustion, IFRF Combustion Journal, 13, 2013, pp. 1-14.
12.  R. Prieler and et al., Numerical investigation of the steady flamelet approach under different combustion environments, Fuel, 140, 2015, pp. 731-743.
13.  B. Mayr and et al., The usability and limits of the steady flamelet approach in oxy-fuel combustions, Energy, 90, 2015, pp. 1478-1489.
14.  R. Prieler and et al., Evaluation of a steady flamelet approach for use in oxy-fuel combustion, Fuel, 118 2014, pp. 55-68.
15.  F. Chitgarha, M. D. Emami and M. Farshchi, Simulation of a CH4/H2 diffusion flame using unsteady and steady flamelet combustion models, Fuel and Combustion, 8, No. 2, 2015, pp. 71-84.
16.  U. Bollettini and et al., Mathematical modeling of oxy-natural gas flames, IFRF Report, International Flame Research Foundation,IJmuiden, Velen, Netherland, 1997.
17.  N. Lallemant, J. Dugue and R. Weber, Analysis of the experimental data collected during the OXYFLAM-1 and OXYFLAM-2 experiments, IFRF Report, International Flame Research Foundation, IJmuiden, Velen, Netherland,1997.
18.  C. Yin, RANS Simulation of Oxy-Natural Gas Combustion, Master Thesis, Board of Studies in Energy, Alborg University, Alborg, 2010.
19.  H. Müller, F. Ferraro and M. Pfitzner, Implementation of a Steady Laminar Flamelet Model for non-premixed combustion in LES and RANS simulations, 8th International OpenFOAM Workshop, Jeju, South Korea, 2013.
20.  H. Pitsch, Combustion Theory, Princeton-CEFRC Summer School On Combustion, Princeton University, USA, Princeton, 2012.
21.  H. Pitsch, M. Chen and N. Peters, Unsteady flamelet modeling of turbulent hydrogen-air diffusion flames, Symposium (international) on combustion, University of Colorado at Boulder, USA, Colorado, August 1998.
22.  ANSYS, A.F., 12.0 Theory Guide T 16. Multiphase Flows, Last Access Oct. 2010.
23.  B. Kashir, S. Tabejamaat and N. Jalalatian, The impact of hydrogen enrichment and bluff-body lip thickness on characteristics of blended propane/hydrogen bluff-body stabilized turbulent diffusion flames, Energy Conversion and Management, 103, 2015, pp. 1-13.
24. E. Ranzi and et al., Hierarchical and comparative kinetic modeling of laminar flame speeds of hydrocarbon and oxygenated fuels, Progress in Energy and Combustion Science, 38, No. 4, pp. 468-501.
25.  G. P.Smith and et al., GRI 3.0 Mechanism, Gas Research Institute (http://www. me. berkeley. edu/gri_mech), Accessed 21 September 2017.
26. M. F. Modest, Radiative Heat Transfer, Third Edition, Amesterdam, Academic press, 2013.