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Journal of Physics: Conference Series | 2013

Biogas Laminar Burning Velocity and Flammability Characteristics in Spark Ignited Premix Combustion

Willyanto Anggono; I. N. G. Wardana; M. Lawes; Kevin J. Hughes; Slamet Wahyudi; Nurkholis Hamidi; Akihiro Hayakawa

Spherically expanding flames propagating at constant pressure were employed to determine the laminar burning velocity and flammability characteristics of biogas-air mixtures in premixed combustion to uncover the fundamental flame propagation characteristics of a new alternative and renewable fuel. The results are compared with those from a methane-air flame. Biogas is a sustainable and renewable fuel that is produced in digestion facilities. The composition of biogas discussed in this paper consists of 66.4% methane, 30.6% carbon dioxide and 3% nitrogen. Burning velocity was measured at various equivalence ratios (ϕ) using a photographic technique in a high pressure fan-stirred bomb, the initial condition being at room temperature and atmospheric pressure. The flame for methane-air mixtures propagates from ϕ=0.6 till ϕ=1.3. The flame at ϕ≥1.4 does not propagate because the combustion reaction is quenched by the larger mass of fuel. At ϕ≤0.5, it does not propagate as well since the heat of reaction is insufficient to burn the mixtures. The flame for biogas-air mixtures propagates in a narrower range, that is from ϕ=0.6 to ϕ=1.2. Different from the methane flame, the biogas flame does not propagate at ϕ≥1.3 because the heat absorbed by inhibitors strengthens the quenching effect by the larger mass of fuel. As in the methane flame, the biogas flame at ϕ≤0.5 does not propagate. This shows that the effect of inhibitors in extremely lean mixtures is small. Compared to a methane-air mixture, the flammability characteristic (flammable region) of biogas becomes narrower in the presence of inhibitors (carbon dioxide and nitrogen) and the presence of inhibitors causes a reduction in the laminar burning velocity. The inhibitor gases work more effectively at rich mixtures because the rich biogas-air mixtures have a higher fraction of carbon dioxide and nitrogen components compared to the lean biogas-air mixtures.


ASME/JSME 2011 8th Thermal Engineering Joint Conference, AJTEC 2011 | 2011

Study of Thermo-Diffusive Effects on Iso-Octane/Air Flames at Fixed Turbulence Karlovitz Number

Akihiro Hayakawa; Tomohiro Takeo; Yukito Miki; Yukihide Nagano; Toshiaki Kitagawa

Spherically propagating laminar and turbulent flames were studied using iso-octane / air mixtures with and without dilution. The main purpose of this study is to clarify the influence of thermo-diffusive effects on the turbulent flames. In order to examine the thermo-diffusive effects solely by separating them from the effects of flame stretch, turbulent burning velocities were compared at constant flame stretch factors. The mean flame stretch factor acting on turbulent flame front may be represented by the turbulence Karlovitz number. Thus, turbulent explosions were carried out at fixed turbulence Karlovitz numbers. The ratio of turbulent burning velocity to unstretched laminar burning velocity increased with the equivalence ratio for non-diluted mixtures at fixed turbulence Karlovitz numbers. And this ratio for CO2 diluted mixtures was larger than N2 diluted mixtures. The Markstein number that denotes the sensitivity of the flame to thermo-diffusive effects depends on the equivalence ratio and diluents of the mixture. The ratio of turbulent burning velocity to unstretched laminar one increased with decreasing Markstein number. Especially, it changed stepwise around Markstein number of zero. However, the burning velocity ratios did not increase with increasing mixture pressure although the Markstein number decreased with pressure.© 2011 ASME


International Journal of Hydrogen Energy | 2008

Turbulent burning velocity of hydrogen-air premixed propagating flames at elevated pressures

Toshiaki Kitagawa; Takashi Nakahara; Kosuke Maruyama; Kunihiro Kado; Akihiro Hayakawa; Shoichi Kobayashi


International Journal of Hydrogen Energy | 2014

Effects of hydrogen concentration on premixed laminar flames of hydrogen-methane-air

Ekenechukwu C. Okafor; Akihiro Hayakawa; Yukihide Nagano; Toshiaki Kitagawa


Journal of Thermal Science and Technology | 2012

Analysis of Turbulent Burning Velocity of Spherically Propagating Premixed Flame with Effective Turbulence Intensity

Akihiro Hayakawa; Yukito Miki; Yukihide Nagano; Toshiaki Kitagawa


9th International Conference on Power Engineering, ICOPE 2009 | 2009

Properties of ethanol laminar and turbulent premixed flames

Kazutaka Ohara; Masayoshi Tsukikawa; Yousuke Araki; Akihiro Hayakawa; Shoichi Kobayashi; Toshiaki Kitagawa


SAE International Powertrains, Fuels and Lubricants Meeting | 2011

Effects of CO 2 and N 2 Dilutions on Laminar and Turbulent Flame Propagation

Akihiro Hayakawa; Yukito Miki; Shoichi Kobayashi; Yukihide Nagano; Toshiaki Kitagawa


Journal of The Japan Institute of Energy | 2010

Effects of pressure on laminar and turbulent burning velocities of ethanol premixed flames

Kazutaka Ohara; Masayoshi Tsukikawa; Yousuke Araki; Akihiro Hayakawa; Shoichi Kobayashi; Yukihide Nagano; Toshiaki Kitagawa


Proceedings of the Combustion Institute | 2018

Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation

Osamu Kurata; Norihiko Iki; Takahiro Inoue; Takayuki Matsunuma; Taku Tsujimura; Hirohide Furutani; Masato Kawano; Keisuke Arai; Ekenechukwu C. Okafor; Akihiro Hayakawa; Hideaki Kobayashi


The Proceedings of the National Symposium on Power and Energy Systems | 2017

Development of low NOx combustor for ammonia combustion gas-turbine power generation

Osamu Kurata; Norihiko Iki; Takayuki Matsunuma; Takahiro Inoue; Taku Tsujimura; Hirohide Furutani; Hideaki Kobayashi; Akihiro Hayakawa

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