No formation and its reduction through co-flow methane  reburn in a pulverised coal combustion process under  various overall equivalence ratio

A cost-effective reduction of NOx emission from utility boilers firing pulverized coal can be achieved by means of combustion modifications in the furnace. It is also essential to provide the pulverized coal diffusion flame control. Mathematical modeling is regularly used for analysis and optimization of complex turbulent reactive flows and mutually dependent processes in coal combustion furnaces. In the numerical study, predictions were performed by an in-house developed comprehensive three-dimensional differential model of flow, combustion and heat/mass transfer with submodel of the fuel- and thermal-NO formation/ destruction reactions. Influence of various operating conditions in the case-study utility boiler tangentially fired furnace, such as distribution of both the fuel and the combustion air over the burners and tiers, fuel-bound nitrogen content and grinding fineness of coal were investigated individually and in combination. Mechanisms of NO formation and depletion were found to be strongly affected by flow, temperature and gas mixture components concentration fields. Proper modifications of combustion process can provide more than 30% of the NOx emission abatement, approaching the corresponding emission limits, with simultaneous control of the flame geometry and position within the furnace. This kind of complex numerical experiments provides conditions for improvements of the power plant furnaces exploitation, with respect to high efficiency, operation flexibility and low emission.

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00/00970 Approaches to modelling heterogeneous char NO formation/destruction during pulverised coal combustion

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(00)90947-0 ◽

2000 ◽

Vol 41 (2) ◽

pp. 107

Keyword(s):

Coal Combustion ◽

No Formation ◽

Pulverised Coal

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Approaches to modelling heterogeneous char NO formation/destruction during Pulverised coal combustion

Carbon ◽

10.1016/s0008-6223(99)00034-2 ◽

1999 ◽

Vol 37 (10) ◽

pp. 1545-1552 ◽

Cited By ~ 41

Author(s):

J.M. Jones ◽

P.M. Patterson ◽

M. Pourkashanian ◽

A. Williams

Keyword(s):

Coal Combustion ◽

No Formation ◽

Pulverised Coal

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Pulverised-Coal Combustion with Staged Air Introduction: CFD Analysis with Different Thermal Radiation Methods~!2009-08-21~!2009-10-13~!2010-04-16~!

The Open Thermodynamics Journal ◽

10.2174/1874396x01004020002 ◽

2010 ◽

Vol 4 (2) ◽

pp. 2-12 ◽

Cited By ~ 1

Author(s):

Risto V. Filkoski

Keyword(s):

Thermal Radiation ◽

Coal Combustion ◽

Cfd Analysis ◽

Pulverised Coal

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Emission Characteristics for Swirl Methane–Air Premixed Flames with Ammonia Addition

Energies ◽

10.3390/en14030662 ◽

2021 ◽

Vol 14 (3) ◽

pp. 662

Author(s):

Joanna Jójka ◽

Rafał Ślefarski

Keyword(s):

Equivalence Ratio ◽

Combustion Process ◽

Great Influence ◽

Emission Characteristics ◽

Firing Rates ◽

Numerical Tests ◽

Ammonia Addition ◽

Swirl Flame ◽

Reactor Network ◽

No Emissions

This paper details the experimental and numerical analysis of a combustion process for atmospheric swirl burners using methane with added ammonia as fuel. The research was carried out for lean methane–air mixtures, which were doped with ammonia up to 5% and preheated up to 473 K. A flow with internal recirculation was induced by burners with different outflow angles from swirling blades, 30° and 50°, where tested equivalence ratio was 0.71. The NO and CO distribution profiles on specified axial positions of the combustor and the overall emission levels at the combustor outlet were measured and compared to a modelled outcome. The highest values of the NO emissions were collected for 5% NH3 and 50° (1950 ppmv), while a reduction to 1585 ppmv was observed at 30°. The doubling of the firing rates from 15 kW up to 30 kW did not have any great influence on the overall emissions. The emission trend lines were not proportional to the raising share of the ammonia in the fuel. 3D numerical tests and a kinetic study with a reactor network showed that the NO outlet concentration for swirl flame depended on the recirculation ratio, residence time, wall temperature, and the mechanism used. Those parameters need to be carefully defined in order to get highly accurate NO predictions—both for 3D simulations and simplified reactor-based models.

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Simulation of Thermal Effects on the Flow Field in a Pilot-Scale Kiln

Mining Metallurgy & Exploration ◽

10.1007/s42461-021-00422-x ◽

2021 ◽

Author(s):

I. A. Sofia Larsson ◽

Anna-Lena Ljung ◽

B. Daniel Marjavaara

Keyword(s):

Flow Field ◽

Coal Combustion ◽

Thermal Effects ◽

Iron Ore ◽

Combustion Process ◽

Pilot Scale ◽

Mixing Properties ◽

Process Gas ◽

Mixing Rates ◽

Computational Fluid Dynamics Cfd

AbstractThe flow field and coal combustion process in a pilot-scale iron ore pelletizing kiln is simulated using a computational fluid dynamics (CFD) model. The objective of the work is to investigate how the thermal effects from the flame affect the flow field. As expected, the combustion process with the resulting temperature rise and volume expansion leads to an increase of the velocity in the kiln. Apart from that, the overall flow field looks similar regardless of whether combustion is present or not. The flow field though affects the combustion process by controlling the mixing rates of fuel and air, governing the flame propagation. This shows the importance of correctly predicting the flow field in this type of kiln, with a large amount of process gas circulating, in order to optimize the combustion process. The results also justify the use of down-scaled, geometrically similar, water models to investigate kiln aerodynamics in general and mixing properties in particular. Even if the heat release from the flame is neglected, valuable conclusions regarding the flow field can still be drawn.

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Study on the Effect of Adiabatic Flame Temperature on NOx Formation Using Ethanol Gasoline Blend in SI Engine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.781-784.2471 ◽

2013 ◽

Vol 781-784 ◽

pp. 2471-2475 ◽

Cited By ~ 5

Author(s):

B. M. Masum ◽

M.A. Kalam ◽

H.H. Masjuki ◽

S. M. Palash

Keyword(s):

Equivalence Ratio ◽

Gasoline Engine ◽

Flame Temperature ◽

Inlet Temperature ◽

Si Engine ◽

Nox Formation ◽

Adiabatic Flame Temperature ◽

No Formation ◽

Blended Fuel ◽

Active Research

Active research and development on using ethanol fuel in gasoline engine had been done for few decades since ethanol served as a potential of infinite fuel supply. This paper discussed analytically and provides data on the effects of compression ratio, equivalence ratio, inlet temperature, inlet pressure and ethanol blend in cylinder adiabatic flame temperature (AFT) and nitrogen oxide (NO) formation of a gasoline engine. Olikara and Borman routines were used to calculate the equilibrium products of combustion for ethanol gasoline blended fuel. The equilibrium values of each species were used to predict AFT and the NO formation of combustion chamber. The result shows that both adiabatic flame temperature and NO formation are lower for ethanol-gasoline blend than gasoline fuel.

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