Numerical Study of the Effect of the Diameter of Alumina Balls on Flame Stabilization in a Porous-Medium Burner

Bubnovich, V.; Henríquez, Luis Castillo; Gnesdilov, N.N.

doi:10.1080/00397910601149942

Cited by 47 publications

(20 citation statements)

References 32 publications

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“…Based on the above reviews, the published studies of [1][2][3][4][5][6][7][8][9][10][11][12] separately focused on the inert porous media combustion. In addition, most of the previous studies of [13][14][15][16][17][18][19][20][21][22][23][24][25][26] on catalytic combustion mainly independently involved the catalyst preparations, the supports selections, or the application optimizations.…”

Section: Introductionmentioning

confidence: 99%

“…The local temperature and species distributions showed that the structure of submerged flames involved a broad reaction zone and the temperature distributions revealed that the reaction zone moved upstream as the firing rate increased. Bubnovich et al [5,6] experimentally and numerically studied lean methane-air mixtures combustion in a porous media combustor formed by two beds of different sizes of alumina balls. Results concluded that the pollutants emissions increased and the stable combustion regions enlarged with increase in equivalence ratio.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Catalytic combustion of premixed methane/air in a two-zone perovskite-based alumina pileup-pellets burner with different pellet diameters

Xiao

2015

Fuel

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Catalytic combustion of premixed methane/air in a two-zone perovskite-based alumina pileup-pellets burner with different pellet diameters

Xiao

2015

Fuel

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“…In recent years, a number of research papers have covered a wide range of studies in porous media [5][6][7][8][9][10][11][12][13][14][15][16][17][18], including flows parallel to a layer of porous material [19], across permeable baffles [20,21], and porous inserts [22]. Investigation on configurations concerning perpendicular jets into a porous core is much needed for optimization of heat sinks attached to solid surfaces.…”

Section: Introductionmentioning

confidence: 99%

Thermal Analysis of an Impinging Jet on a Plate With and Without a Porous Layer

Lemos

Fischer

2008

Numerical Heat Transfer, Part A: Applications

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This work shows numerical results for a jet impinging against a flat plane covered with a layer of a porous material, which is maintained at a higher temperature than the incoming fluid. Parameters such as permeability and thickness of the porous layer and thermal conductivity ration are varied in order to analyze their effects on the local distribution of Nu. The macroscopic equations for mass, momentum, and energy are obtained based on a volumeaverage concept. The numerical technique employed for discretizing the governing equations was the control volume method with a boundary-fitted nonorthogonal coordinate system. The SIMPLE algorithm was used to handle the pressure-velocity coupling. Results indicate that inclusion of a porous layer decreases the peak in Nu avoiding excessive heating or cooling at the stagnation point. Also found was that the integral heat flux from the wall is enhanced for certain range of values of layer thickness, porosity, and thermal conductivity ratio.

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“…Something similar occurs with combustion wave movements in porous cylindrical media: increasing the value of Φ changes the superadiabatic regime to subadiabatic. However, a notorious change is also observed in the u FC = f(u g0 ) functionality for any value of Φ: the almost straight lines located absolutely above or below the horizontal axis of u g0 in the case of annular geometry (see figures 5, 10, 12 and 14) are changed for downward concave curves that cross axis u g0 at some point in circular geometry [10]. In short, for a fixed Φ, the u FC combustion front velocity keeps the same sign (travel direction) regardless of the value of u g0 .…”

Section: Resultsmentioning

confidence: 98%

Filtration Gas Combustion in a Porous Ceramic Annular Burner for Thermoelectric Power Conversion

Bubnovich

Martin

Henríquez

et al. 2018

Heat Transfer Engineering

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A numerical study of the combustion of lean methane/air mixtures in a porous media burner is performed using a novelty geometry, cylindrical annular space. The combustion process takes place in the porous annular space located between two pipes, which are filled with alumina beads of 5.6 mm diameter (Al 2 O 3 ) forming a porosity of 0.4. The outer tube diameter of 3.82 cm is isolated; meanwhile the inner tube of 2 cm in diameter is covered by a continuous set of thermoelectric elements (TEE) for transforming heat energy into electricity. To achieve and maintain the proper temperature gradient on TEE, convective heat losses are considered from the TEE. The respective heat transfer coefficient is variable and is in the range 800 < h < 1500 [W / m 2 ]. The 2D mathematical model includes the energy equations for solid and gas phases, the momentum equations, the continuity equation, the fuel mass conservation, the perfect gas law and it is solved by Means of computational simulations in COMSOL Multiphysics. Computer simulations focus on the two-dimensional temperature analysis and displacement dynamics of the combustion front inside the reactor, depending on the values of the filtration velocity (0.1 < u g0 < 1.0, m/s) and the fuel equivalence ratio (0.06 < Φ < 0. The study shows that the cylindrical annular geometry can be used for converting the energy of combustion from lean gas mixtures into electricity, with a performance similar to the specified by manufacturers of TEEs. INTRODUCTIONThe need to lower emissions and increase efficiency in fossil fuel combustion has driven the search of new combustion methods and advanced burner designs. A porous media burner can provide a good solution due to a number of advantages compared to conventional free-flame combustion, such as large power variation range, high efficiency, compact structure with very high energy concentration per unit volume, extremely low CO and NO x emissions over a wide range of thermal loads, stable combustion over a wide range of equivalence ratios, 0.4 < Φ < 0.9 [1][2][3]. All the arguments mentioned above have driven the current development of these kinds of burners, which have already found several important industrial applications [4-

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Numerical Study of the Effect of the Diameter of Alumina Balls on Flame Stabilization in a Porous-Medium Burner

Cited by 47 publications

References 32 publications

Catalytic combustion of premixed methane/air in a two-zone perovskite-based alumina pileup-pellets burner with different pellet diameters

Catalytic combustion of premixed methane/air in a two-zone perovskite-based alumina pileup-pellets burner with different pellet diameters

Thermal Analysis of an Impinging Jet on a Plate With and Without a Porous Layer

Filtration Gas Combustion in a Porous Ceramic Annular Burner for Thermoelectric Power Conversion

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