Numerical Studies on Combustion Characteristics of Interacting Pulverized Coal Particles at Various Oxygen Concentration

Cho, Chong Pyo; Jo, Sangpil; Kim, Ho Young; Yoon, Sam S.

doi:10.1080/10407780701446549

Cited by 22 publications

(4 citation statements)

References 15 publications

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“…In eq , the values of the kinetic parameters, which play an important role in the model prediction, are constant. There have been many studies focused on the optimization of the kinetic parameters. ,, The values of the kinetic parameters from Ubhayakar et al are commonly used in coal combustion simulations, and they are employed in the present study.…”

Section: Methodsmentioning

confidence: 99%

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Numerical Studies of Coal Devolatilization Characteristics with Gas Temperature Fluctuation

et al. 2018

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In the present work, coal devolatilization characteristics in a hot gaseous environment with gas temperature fluctuation are investigated numerically with the chemical percolation devolatilization (CPD) model and the two-step (TS) model in a zero-dimensional configuration. The numerical results are first validated against the experimental data, showing that the CPD model can reproduce the coal devolatilization process well. The effects of mean gas temperature, gas temperature fluctuation amplitude, and coal particle size on coal devolatilization are then explored. The particle temperature is found to fluctuate with the gas temperature fluctuation at the same frequency. However, the particle temperature shows a delay in responding to the gas temperature fluctuation, with smaller particles having a shorter delay time. It is also found that the gas temperature fluctuation facilitates coal devolatilization. In particular, higher mean gas temperature and fluctuation amplitude values reduce the start time of the devolatilization and result in higher total volatile and tar yields. Smaller particles are more sensitive to gas temperature fluctuation and are easier and faster to devolatilize, producing more volatiles and tar. Compared to the CPD model, the devolatilization process predicted by the TS model generally starts earlier and the final volatile yield is overestimated. Moreover, the TS model predictions have a shorter delay time and larger fluctuation amplitude of coal particle temperature compared to the CPD model predictions, which indicates that the TS model is more apt to be affected by gas temperature fluctuation than the CPD model.

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Section: Methodsmentioning

confidence: 99%

“…There have been many studies focused on the optimization of the kinetic parameters. 11,20,21 The values of the kinetic parameters from Ubhayakar et al 15 are commonly used in coal combustion simulations, and they are employed in the present study.…”

Section: Methodsmentioning

confidence: 99%

Numerical Studies of Coal Devolatilization Characteristics with Gas Temperature Fluctuation

et al. 2018

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“…4. Распределение концентрации углекислого газа по длине топочной камеры в разных сечениях: z -расстояние от горелки а) одностадийное приближение выхода летучих веществ б) двухстадийная модель выхода летучих веществ [13] (кг/с) в) двухстадийная модель выхода летучих веществ [12] г) многостадийная модель CPD [14] д) двухстадийная модель выхода летучих веществ [11] Рис. 5.…”

Section: результаты исследования влияния модели выхода летучих веществunclassified

Numerical Study of Devolatilization Models on the Combustion Process of Pulverized Fuel Flow Swirling

Кузнецов¹,

Дектерев²,

Sentyabov³

et al. 2016

J. Sib. Fed. Univ. Eng. technol.

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“…Over the years, there has been a large amount of sustained research on the combustion behavior of single particles of coal and biomass (including Refs [46, 47, 50, 51, 63-66, 68, 69, 71]). Some research has also been performed on the combustion behavior of groups of particles of coal (see for instance Refs [95][96][97][98][99][100][101][102][103][104][105]).…”

Section: Introductionmentioning

confidence: 99%

On the combustion parameters of coal, biomass and iron, burning either as isolated particles or in groups of particles

Yao

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In this research, combustion characteristics of pulverized solid fuels, including bituminous coal, various biomass types, and iron, were investigated with experimental methods. Emphasis was placed on obtaining radiative parameters for these fuels, including spectral emissivity, temperature and soot volume fractions. Moreover, the structural development of the chars of bituminous coal and various biomass samples, upon devolatilization, was studied by using experimental data and a numerical model. Such measurements can be used in the development of predictive numerical models for the operation and emissions of furnaces. The experimental methods that were used in this study included three-color pyrometry, spectrometry and highspeed cinematography. The following results were obtained: (i) For single particle combustion of coal and three types of biomasses, all three experimental methods were used to measure the combustion temperatures, spectral emissivities and soot volume fractions. The spectral emissivities of the chars volatile matter flames those fuels were measured, and average peak temperatures and 2D temperature distribution were identified. (ii) For group particles combustion of coal and biomasses, the spectrometer and high-speed camera were used to measure the combustion temperatures, spectral emissivities and soot volume fractions. Average spectral emissivities and mean particle cloud temperatures were measured for two different particle number densities (PNDs) of these fuels in the furnace. (iii) For iron combustion, all three experimental methods were used to measure the combustion temperatures and spectral emissivities for single particle combustion and only the spectrometer and high-speed camera for group combustion. Average spectral emissivities of single particles for different oxygen concentration and groups of iron particles burning in air at different PNDs were measured. Corresponding average temperatures and 2D temperature distribution of single particles and groups combustion of iron were also measured. (iv) The numerical model, which was used in this work, is a kinetic model that was designed for char combustion of biomass which requires an experimental temperature profile. The model was used to determine the size and overall porosity (pore volume) of carbonaceous chars, originating from high-heating rates and hightemperature pyrolysis and/or combustion of biomass. The average char porosities (effective porosities) of several raw and torrefied biomass particles were calculated to be in the range of 92-95%. The average initial dimension of the chars, upon rapid pyrolysis, was in the range of 50-60% mid-value of the mesh size of the sieves used to size-classify their highly irregular parent biomass particles. Finally, this dissertation presents measurements and calculations of multiple critical combustion parameters for different fuels. It provides important information and lays the foundation for subsequent experimental research and applications for those renewable fuels. The combination of spect...

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Numerical Studies on Combustion Characteristics of Interacting Pulverized Coal Particles at Various Oxygen Concentration

Cited by 22 publications

References 15 publications

Numerical Studies of Coal Devolatilization Characteristics with Gas Temperature Fluctuation

Numerical Studies of Coal Devolatilization Characteristics with Gas Temperature Fluctuation

Numerical Study of Devolatilization Models on the Combustion Process of Pulverized Fuel Flow Swirling

On the combustion parameters of coal, biomass and iron, burning either as isolated particles or in groups of particles

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